FAA-H-8083-4 Helicopter Instructor’s Handbook, 2012

Helicopter Instructor’s Handbook 2012 U.S. Department of Transportation FEDERAL AVIATION ADMINISTRATION Flight Standards Service

ii

Preface The Helicopter Instructor’s Handbook is designed as a technical manual for applicants who are preparing for their flight instructor pilot certificate with a helicopter class rating. This handbook contains detailed coverage of aerodynamics, flight controls, systems, performance, flight maneuvers, emergencies, and aeronautical decision-making. Topics such as weather, navigation, radio navigation and communications, use of flight information publications, and regulations are available in other Federal Aviation Administration (FAA) publications. This handbook conforms to flight instructor pilot training and certification concepts established by the FAA. There are different ways of teaching, as well as performing flight procedures and maneuvers, and many variations in the explanations of aerodynamic theories and principles. Occasionally the word “must” or similar language is used where the desired action is deemed critical. The use of such language is not intended to add to, interpret, or relieve a duty imposed by Title 14 of the Code of Federal Regulations (14 CFR). This handbook is available for download, in PDF format, from www.faa.gov. This handbook is published by the United States Department of Transportation, Federal Aviation Administration, Airman Testing Standards Branch, AFS-630, P.O. Box 25082, Oklahoma City, OK 73125. Comments regarding this publication should be sent, in email form, to the following address: [email protected] iii

iv

Acknowledgments The Helicopter Instructor’s Handbook was produced by the Federal Aviation Administration (FAA) with the assistance of Safety Research Corporation of America (SRCA). The FAA wishes to acknowledge the following contributors: NZ Civil Aviation Authority for image of safety procedures for approaching a helicopter (Chapter 1) David Park (www.freedigitalphotos.net) for image used in Chapter 2 Paul Whetstone (www.meyersaircraft.com) for image used in Chapter 5 Burkhard Domke (www.b-domke.de) for images used in Chapter 5 Bishop Equipment Mfg. Inc (www.bishopequipment.com) for image used in Chapter 6 Terry Simpkins of FLYIT Simulators (www.flyit.com) for image used in Chapter 13 Additional appreciation is extended to W.A. (Dub) Blessing, HAI Outstanding CFI award 1985; Donovan L. Harvey (1928 to 2000), HAI Outstanding CFI award 1987; Neil Jones, CFI; Chin Tu, CFI; the Helicopter Association International (HAI), Aircraft Owners and Pilots Association (AOPA), and the AOPA Air Safety Foundation for their technical support and input. v

vi

Table of Contents Preface....................................................................iii Thrust..........................................................................3-4 Drag.............................................................................3-5 Acknowledgments..................................................v Airfoil.............................................................................3-6 Blade Twist.................................................................3-6 Table of Contents..................................................vii Rotor Blade and Hub Definitions...................................3-7 Airflow and Reactions in the Rotor System...................3-7 Chapter 1 Rotor Blade Angles........................................................3-8 Introduction to Flight Training............................1-1 Hovering Flight..............................................................3-8 Purpose of Flight Training..............................................1-1 Translating Tendency or Drift......................................3-10 Practical Flight Instructor Strategies..............................1-2 Pendular Action............................................................3-10 The Federal Aviation Administration (FAA).................1-3 Coning .........................................................................3-10 Coriolis Effect (Law of Conservation of Angular Role.............................................................................1-3 Momentum)..................................................................3-11 FAA Reference Material.............................................1-3 Ground Effect ..............................................................3-11 Role of the Examiner......................................................1-5 Gyroscopic Precession..................................................3-12 Role of the Certificated Flight Instructor (CFI)..............1-5 Forward Flight..............................................................3-12 Flight Safety Practices....................................................1-6 Translational Lift..........................................................3-12 Helicopter Hazards.........................................................1-6 Translational Thrust......................................................3-13 Instructional Hazards......................................................1-8 Induced Flow................................................................3-13 Collision Avoidance.......................................................1-9 Transverse Flow Effect.................................................3-13 See and Avoid.............................................................1-9 Dissymmetry of Lift.....................................................3-13 Positive Exchange of Flight Controls.......................1-10 Hover.........................................................................3-13 Single-Pilot Resource Management (SRM).................1-10 Translational Flight...................................................3-14 Risk Management.........................................................1-11 Sideward, Rearward, and Turning Flight.....................3-14 Chapter Summary.........................................................1-12 Autorotation..................................................................3-15 Entry..........................................................................3-15 Chapter 2 Steady-State Descent................................................3-15 Introduction to the Helicopter.............................2-1 Deceleration..............................................................3-15 Introduction....................................................................2-1 Instructor Tips..............................................................3-16 Chapter Summary.........................................................3-16 Training Procedures....................................................2-2 Introduction to the Helicopter.....................................2-2 Chapter 4 Introduction to Flying.................................................2-3 Helicopter Flight Controls...................................4-1 Instructor Tips................................................................2-4 Introduction....................................................................4-1 Chapter Summary...........................................................2-6 Collective Pitch Control.................................................4-2 Throttle Control..............................................................4-3 Chapter 3 Cyclic Pitch Control ......................................................4-4 Aerodynamics of Flight.......................................3-1 Antitorque Control..........................................................4-5 Introduction....................................................................3-1 Practice...........................................................................4-6 Forces Acting on the Aircraft.........................................3-2 Instructor Tips................................................................4-6 Chapter Summary...........................................................4-6 Lift...............................................................................3-2 Bernoulli’s Principle...............................................3-2 Newton’s Laws of Motion.......................................3-2 vii

Chapter 5 Environmental Systems (Heating/Cooling)..............5-25 Helicopter Components, Sections, and Anti-Icing Systems....................................................5-25 Systems................................................................5-1 Introduction....................................................................5-1 Engine Anti-Ice.....................................................5-25 Carburetor Icing....................................................5-25 Airframe Design..........................................................5-2 Preflight and Deicing.............................................5-26 Rotor Blade Design.....................................................5-2 Instructor Tips..............................................................5-26 Powerplant Design......................................................5-2 Chapter Summary.........................................................5-26 Antitorque System Design..........................................5-2 Landing Gear System Design.....................................5-2 Chapter 6 Airframe. ........................................................................ 5-2 Rotorcraft Flight Manual......................................6-1 Aluminum...................................................................5-3 Introduction....................................................................6-1 Introducing the Manual..................................................6-2 Advantages..............................................................5-3 Sections of the Manual...................................................6-2 Disadvantages..........................................................5-3 General Information (Section 1).................................6-2 Operating Limitations (Section 2)..............................6-2 Composite Construction..............................................5-4 Emergency Procedures (Section 3).............................6-4 Advantages..............................................................5-4 Normal Procedures (Section 4)...................................6-4 Performance (Section 5).............................................6-5 Disadvantages..........................................................5-4 Weight and Balance (Section 6).................................6-6 Aircraft and Systems Description (Section 7)............6-6 Fuselage..........................................................................5-4 Handling, Servicing, and Maintenance (Section 8)....6-6 Main Rotor System.........................................................5-4 Supplements (Section 9).............................................6-7 Chapter Summary...........................................................6-8 Rigid Rotor System.....................................................5-5 Semirigid Rotor System..............................................5-5 Chapter 7 Fully Articulated Rotor System..................................5-8 Weight and Balance.............................................7-1 Bearingless Rotor System.........................................5-10 Introduction....................................................................7-1 Tandem Rotor...........................................................5-10 Weight............................................................................7-2 Coaxial Rotor System...............................................5-11 Swashplate Assembly...............................................5-12 Definitions...................................................................7-2 Antitorque Systems......................................................5-14 Determining Empty Weight........................................7-2 Tail Rotor..................................................................5-14 Balance...........................................................................7-3 Other Types of Antitorque System...........................5-14 Center of Gravity (CG)...............................................7-3 Engines.........................................................................5-16 Reciprocating Engine (Piston)..................................5-16 CG Forward of Forward Limit................................7-3 Turbine Engine..........................................................5-16 CG Aft of Aft Limit................................................7-3 Compressor...............................................................5-18 Lateral Balance...........................................................7-4 Combustion Chamber...............................................5-18 Ballast. ........................................................................ 7-4 Turbine......................................................................5-18 Weight and Balance Calculations...................................7-4 Transmission System....................................................5-19 Weight Versus Aircraft Performance..........................7-5 Main Rotor Transmission.........................................5-19 Arm (Station)..............................................................7-5 Antitorque Drive System..........................................5-20 Moment.......................................................................7-5 Clutch........................................................................5-20 Weight and Balance Methods.....................................7-6 Freewheeling Unit.....................................................5-20 Computational Method............................................7-6 Fuel System..................................................................5-21 Loading Chart Method ...........................................7-6 Engines.........................................................................5-21 Combination Method...............................................7-8 Reciprocating Engines..............................................5-21 Calculating Lateral CG............................................7-9 Instructor Tips..............................................................7-10 Carburetor..............................................................5-21 Chapter Summary.........................................................7-10 Carburetor Ice........................................................5-22 Chapter 8 Helicopter Performance.......................................8-1 Fuel Injection.........................................................5-22 Introduction....................................................................8-1 Electrical Systems........................................................5-23 Hydraulics.....................................................................5-23 Hydraulic System Components.................................5-23 Hydraulic System Failure.........................................5-24 Stability Augmentation Systems (SAS).......................5-24 Autopilot...................................................................5-25 viii

Factors Affecting Performance.......................................8-2 Normal Descent............................................................10-5 Density Altitude..........................................................8-2 Instructional Points...................................................10-5 Weight.....................................................................8-3 Common Student Difficulties...................................10-5 Loads...........................................................................8-3 Attitude..................................................................10-5 Load Factor.............................................................8-3 Wind............................................................................8-4 Coordination..........................................................10-5 Height/Velocity Diagram...............................................8-4 Scan.......................................................................10-5 Performance Planning....................................................8-5 Instructor Tips................................................................8-5 Turns ............................................................................10-5 Chapter Summary...........................................................8-6 Instructional Points...................................................10-6 Common Student Difficulties...................................10-6 Chapter 9 Attitude..................................................................10-6 Preflight and Postflight Procedures..................9-1 Introduction....................................................................9-1 Leaning Away From a Turn..................................10-6 Checklists. ...................................................................... 9-2 Required Documents......................................................9-2 Failure to Clear the Area.......................................10-6 Preflight Inspection.........................................................9-3 Cockpit Management......................................................9-4 Rolling Out of a Turn............................................10-6 Ground Operations.........................................................9-5 Engine Start....................................................................9-6 Climbing and Descending Turns..................................10-6 Taxiing............................................................................9-7 Instructional Points...................................................10-6 Before Takeoff................................................................9-7 Common Student Difficulties...................................10-7 After Landing.................................................................9-7 Attitude..................................................................10-7 Parking............................................................................9-7 Engine Shutdown............................................................9-9 Scan.......................................................................10-7 Postflight.........................................................................9-9 Securing and Servicing...................................................9-9 Coordination Exercises ............................................10-7 Instructor Tip..................................................................9-9 Approaches...................................................................10-7 Chapter Summary...........................................................9-9 Instructional Points...................................................10-8 Chapter 10 Common Student Difficulties...................................10-8 Basic Flight Maneuvers.....................................10-1 Introduction..................................................................10-1 Ground Track........................................................10-8 Basic Maneuvers..........................................................10-2 Straight-and-Level Flight.............................................10-2 Altitude..................................................................10-8 Instructional Points...................................................10-2 Airspeed. ............................................................... 10-8 Common Student Difficulties...................................10-3 Approach Angle....................................................10-8 Visualizing Attitude..............................................10-3 Overcontrolling.....................................................10-3 Traffic....................................................................10-9 Trim.......................................................................10-3 Coordination..........................................................10-3 Power Adjustments...............................................10-9 Scan.......................................................................10-3 Kinesthesia............................................................10-3 Go-Around....................................................................10-9 Normal Climb...............................................................10-4 Instructional Points...................................................10-9 Instructional Points...................................................10-4 Common Student Difficulties...................................10-9 Common Student Difficulties...................................10-4 Initiating the Go-Around.......................................10-9 Attitude..................................................................10-4 Overcontrolling.....................................................10-4 Coordination..........................................................10-9 Coordination..........................................................10-5 Scan.......................................................................10-5 Normal and Crosswind Takeoff From a Hover............10-9 Instructional Points...................................................10-9 Crosswind Considerations During Takeoffs...........10-10 Common Student Difficulties.................................10-10 Attitude Control...................................................10-10 Heading Control..................................................10-10 Crosswind Corrections........................................10-10 Traffic..................................................................10-11 Hovering.....................................................................10-11 Vertical Takeoff to a Hover and Hovering.............10-11 Instructional Points..............................................10-11 Common Student Difficulties..............................10-13 Hovering Turn.........................................................10-14 Instructional Points..............................................10-14 Common Student Difficulties..............................10-15 ix

Hovering Forward...................................................10-16 Rapid Deceleration or Quick Stop................................11-6 Instructional Points..............................................10-16 Instructional Points...................................................11-6 Common Student Difficulties...................................11-7 Common Student Difficulties..............................10-16 Coordination..........................................................11-7 Hovering Sideward.................................................10-16 Recovery................................................................11-7 Common Student Difficulties..............................10-17 Steep Approach to a Hover...........................................11-7 Hovering Rearward.................................................10-17 Instructional Points...................................................11-8 Instructional Points..............................................10-17 Common Student Difficulties...................................11-8 Common Student Difficulties..............................10-17 Shallow Approach and Running/Roll-On Landing......11-8 Instructional Points...................................................11-9 Landing From a Hover............................................10-18 Common Student Difficulties...................................11-9 Instructional Points..............................................10-18 Approach Angle....................................................11-9 Common Student Difficulties..............................10-18 Attitude Control.....................................................11-9 Taxi.............................................................................10-19 Collective Control...............................................11-10 Air Taxi...................................................................10-19 Surface/Ground Taxi...............................................10-19 Touchdown..........................................................11-10 Instructional Points.................................................10-19 Slope Operations........................................................11-10 Ground Reference Maneuvers....................................10-20 Slope Landings........................................................11-10 Rectangular Course.................................................10-20 Instructional Points..............................................11-11 S-Turn.....................................................................10-21 Turns Around a Point..............................................10-21 Common Student Difficulties..............................11-12 Common Student Difficulties.................................10-22 Failure To Plan Properly.....................................10-22 Slope Takeoff..........................................................11-12 Instructional Points..............................................11-12 Coordination........................................................10-22 Common Student Difficulties..............................11-12 Division of Attention...........................................10-22 Confined Area Operations..........................................11-12 Attitude................................................................10-22 Instructional Points.................................................11-13 Approach and Landing........................................11-13 Scan.....................................................................10-22 Takeoff................................................................11-14 Instructor Tips............................................................10-22 Chapter Summary.......................................................10-24 Common Student Difficulties.................................11-15 Pinnacle and Ridgeline Operations............................11-15 Chapter 11 Advanced Flight Maneuvers.............................11-1 Pinnacle Landings...................................................11-15 Introduction..................................................................11-1 Instructional Points.................................................11-15 Instructor’s Approach...................................................11-2 Common Student Difficulties.................................11-16 Scenario-Based Training...........................................11-2 Planning...............................................................11-16 Identification, Prevention, and Recovery..................11-2 Reinforce Fundamentals...........................................11-2 Approach Angle..................................................11-16 Reconnaissance Procedures..........................................11-2 High Reconnaissance................................................11-3 Airspeed. ............................................................. 11-16 Low Reconnaissance.................................................11-3 Ground Reconnaissance............................................11-4 Pinnacle Takeoff and Climb.......................................11-16 Maximum Performance Takeoff..................................11-4 Instructional Points.................................................11-16 Instructional Points...................................................11-4 Common Student Difficulties.................................11-16 Common Student Difficulties...................................11-5 Planning...............................................................11-16 Coordination..........................................................11-5 RPM. ................................................................... 11-17 Airspeed. ............................................................... 11-5 Airspeed. ............................................................. 11-17 Running/Rolling Takeoff..............................................11-5 Night Flying................................................................11-17 Instructional Points...................................................11-5 Common Student Difficulties.................................11-17 Common Student Difficulties...................................11-6 Takeoff................................................................11-17 RPM. ..................................................................... 11-6 Airborne. ............................................................. 11-17 Attitude Control.....................................................11-6 Approach.............................................................11-17 Wind......................................................................11-6 Instructional Points.................................................11-17 Cross-Country Operations..........................................11-18 Instructional Points.................................................11-18 Common Student Difficulties.................................11-18 x

Poor Cross-Country Planning..............................11-18 Student Tendencies...................................................13-5 Reliability on Navigation Equipment..................11-18 Instructional Objectives................................................13-6 Instructor Tips............................................................11-18 Instructor Tips..............................................................13-6 Chapter Summary.......................................................11-20 Chapter Summary.........................................................13-7 Chapter 12 Chapter 14 Helicopter Emergencies....................................12-1 Night Operations................................................14-1 Introduction..................................................................12-1 Introduction..................................................................14-1 Autorotative Descents..................................................12-2 Instructor’s Objective...................................................14-2 Eye Anatomy and Physiology......................................14-2 Straight-In Autorotation, With Instructional Points. ....................................................................... 12-2 Visual Problems........................................................14-2 Autorotations With Turns, With Instructional Night Vision Protection............................................14-2 Points. ....................................................................... 12-4 Self-Imposed Stress..................................................14-4 Power Recovery From Practice Autorotation, Scanning Techniques................................................14-4 With Instructional Points..........................................12-4 Visual Illusions.........................................................14-5 Power Failure in a Hover, With Instructional Flight Instruction..........................................................14-6 Points. ....................................................................... 12-5 Preflight Inspection...................................................14-7 Instructor Tips............................................................14-10 Common Student Difficulties With Autorotation.....12-5 Chapter Summary.......................................................14-10 Emergency Situations for Discussion Only..................12-5 Chapter 15 Vortex Ring State (Settling With Power).................12-6 Helicopter Operations........................................15-1 Retreating Blade Stall...............................................12-7 Introduction..................................................................15-1 Ground Resonance....................................................12-7 Collision Avoidance.....................................................15-2 Low-G Conditions and Mast Bumping.....................12-8 Runway Incursions.......................................................15-2 Low Rotor RPM........................................................12-9 Safety Considerations...................................................15-2 Traffic Patterns.............................................................15-2 Blade Stall.............................................................12-9 Instructional Points...................................................15-3 Recovery From Low Rotor RPM..........................12-9 Common Student Difficulties...................................15-4 Common Student Difficulties.................................12-10 Drift Correction.....................................................15-4 Brownout/Whiteout.............................................12-10 Spacing From Other Aircraft.................................15-4 System or Equipment Malfunctions...........................12-11 Antitorque System Failure......................................12-11 Altitude and Airspeed............................................15-4 Complete Loss of Tail Rotor Thrust...................12-11 Airspace........................................................................15-5 Fixed Pitch Settings.............................................12-11 Helicopter Turbine and Multiengine Transition...........15-5 Floats, Wheeled Landing Gear, or Ski Transitions .....15-5 Loss of Tail Rotor Components..........................12-11 Floats.........................................................................15-6 Unanticipated Yaw/Loss of Tail Rotor Wheeled Landing Gear.............................................15-7 Effectiveness (LTE)............................................12-11 Skis............................................................................15-7 External Loads..............................................................15-7 Main Drive Shaft Failure........................................12-12 Personnel...................................................................15-7 Hydraulic Failure....................................................12-12 Knowledge and Skill.................................................15-7 Governor Failure.....................................................12-12 Emergency Procedures..............................................15-8 Multiengine Operations With One Engine Instructor Tips..............................................................15-8 Inoperative..............................................................12-12 Chapter Summary.........................................................15-8 Emergency Equipment and Survival Gear.................12-12 Scenario-Based Training............................................12-13 Instructor Tips............................................................12-14 Chapter Summary.......................................................12-14 Chapter 13 Chapter 16 Attitude Instrument Flying................................13-1 Practical Examination and Preparation for Flight Introduction..................................................................13-1 Review.................................................................16-1 Instructor’s Objective...................................................13-2 Introduction..................................................................16-1 Ground Instruction........................................................13-2 Documentation. ............................................................ 16-1 Flight Instruction..........................................................13-3 Preparing the Student...................................................16-2 Instructional Techniques...........................................13-4 Last Training Flight..................................................16-2 xi

Application and Testing Preparation........................16-2 FAA Resources.........................................................17-5 Preparation for a Practical Exam..................................16-2 Human Factors..............................................................17-6 Training.....................................................................16-2 Curiosity: Healthy or Harmful?................................17-6 Flight Review............................................................16-2 Risk Management.........................................................17-6 Who Needs a Flight Review?...................................16-4 Flight Review Requirements.....................................16-4 Assessing Risk..........................................................17-6 Preparation for the Flight Review.............................16-4 Using the 3P To Form Good Safety Habits..............17-7 The PAVE Checklist.................................................17-8 Model or Type of Helicopter Flown.....................16-4 Recognizing Hazardous Attitudes.............................17-8 Nature of Flight Operations...................................16-4 Use of Resources.......................................................17-9 Recency of Flight Experience...............................16-4 Chapter Summary.........................................................16-6 Internal Resources...............................................17-10 External Resources..............................................17-10 Chapter 17 Workload Management...........................................17-11 Single-Pilot Resource Management, Situational Awareness.............................................17-12 Aeronautical Decision-Making, and Risk Obstacles to Maintaining Situational Management.......................................................17-1 Awareness...........................................................17-12 Introduction..................................................................17-1 Operational Pitfalls..............................................17-12 Origins of ADM and SRM ..........................................17-3 Instructor Tips............................................................17-14 Chapter Summary.......................................................17-14 The Decision-Making Process..................................17-3 Defining the Problem............................................17-4 Glossary...............................................................G-1 Choosing a Course of Action................................17-4 Implementing the Decision and Evaluating the Index.......................................................................I-1 Outcome................................................................17-4 Improper Decision-Making Outcomes..................17-5 xii

CIhnaptterr1 oduction to Flight Training Purpose of Flight Training It is the helicopter instructor’s responsibility to discuss the overall purpose of flight training with the student. Explain that the goal of flight training is the acquisition and honing of basic airmanship skills that provide the student with: • An understanding of the principles of flight. • The ability to safely operate a helicopter with competence and precision both on the ground and in the air. • The knowledge required to exercise sound judgment when making decisions affecting operational safety and efficiency. 1-1

Ensure the student understands that a helicopter operates in Figure 1-1. As part of flight training, a pilot instructs a student on a three-dimensional environment and requires specific skills proper techniques for landing at an airport. to control the aircraft: For the helicopter CFI, this means: • Coordination—the ability to use the hands and feet together subconsciously and in the proper relationship • Before the flight—discuss the procedures for the to produce desired results in the helicopter control. exchange of controls, establish scan areas for clearing the aircraft, and establish who is responsible for • Control touch—to develop the ability to sense and initiating immediate action in an emergency. evaluate the varying pressures and resistance of the control surfaces and/or the instructor’s input • During flight—prioritize the tasks of aviating, transmitted through the cockpit flight controls and navigating, and communicating. Instill the importance apply inputs in response to those pressures. of “see and avoid” and utilizing aircraft lighting to be more visible in certain flight conditions. • Timing—the application of muscular coordination at the proper instant to make maneuvering flight a • During landing—conduct stabilized approaches, constant smooth process. maintain proper angle and desired rate of closure on final. Use aeronautical decision-making (ADM) to • Mental comprehension of aerodynamic state, power demonstrate good judgment for go-arounds, wake required versus power available, and hazards present. turbulence avoidance, traffic, and terrain avoidance. Keep in mind that an accomplished pilot demonstrates the • Always—remember that safety is paramount. ability to assess a situation quickly and accurately and to determine the correct procedure to be followed under the Flight instructors have the responsibility of producing the circumstance; to analyze accurately the probable results of safest pilots possible. For that reason, CFIs should tirelessly a given set of circumstances or of a proposed procedure; to encourage each student to learn as much as he or she is capable exercise care and due regard for safety; to gauge accurately of and keep raising the bar toward the ultimate goal. When the performance of the aircraft; and to recognize personal introducing lesson tasks, flight instructors should introduce limitations and limitations of the aircraft and avoid the student to the Practical Test Standards (PTS) and discuss approaching the critical points of each. The development that the minimum acceptable standards for passing a given of airmanship skills requires effort and dedication on the maneuver are stated therein. The CFI must stress to the student part of both the student and the flight instructor. It begins that these are only the minimum standards and that he or she with the first training flight when the instructor encourages should strive for much higher performance. proper habit formation by introducing and modeling safe operating practices. The PTS is not a teaching tool. It is a testing tool. The overall focus of flight training should be on learning, which includes While every aircraft has its own particular flight characteristics, gaining an understanding of why the standards exist and how the purpose of primary and intermediate flight training is not they were determined. [Figure 1-2] Use the PTS as a training to learn how to fly a particular make and model of helicopter; aid. Title 14 of the Code of Federal Regulations (14 CFR) it is to develop skills and safe habits that are transferable to does require specific training for the PTS endorsements, but any helicopter. [Figure 1-1] Basic airmanship skills serve as this should not be presented to the student at the end of the a firm foundation for this. Acquiring necessary airmanship training. The CFI should take into consideration all of the skills during training and demonstrating these skills by flying with precision and safe flying habits allows the pilot to transition easily to more complex helicopters. Remember, the goal of flight training is to become a safe and competent pilot, and that passing required tests for pilot certification is only the first step toward this goal. Practical Flight Instructor Strategies As discussed in Chapter 8 of the Aviation Instructor Handbook, certificated flight instructors (CFIs) should remember they are a role model for the student. The flight instructor should demonstrate good aviation air sense and practices at all times. 1-2

and verify specific fields. IACRA automatically ensures applicants meet regulatory and policy requirements and forwards the FAA Form 8710-1 application and test results to the FAA Airmen Certification Branch. [Figure 1-3] While many younger students interface easily with the Internet, a CFI trains pilots of all ages. Ensuring the student is comfortable using the FAA’s Internet resources is part of a good training program. Figure 1-2. Practical Test Standards. necessary training and strategically plan that training so the student has time to practice and prepare. It is the ultimate goal of the CFI to produce the safest, most competent pilot from his or her course of instruction and take pride in knowing that the student not only passed the test standards but exceeds those standards when conducting any and all helicopter procedures, on the ground or in the air. The Federal Aviation Administration Figure 1-3. IACRA processes applications for airman certification (FAA) via the Internet and automatically ensures applicants meet regulatory and policy requirements through programming rules Role and data validation. It is imperative that a new student be introduced and become familiar with the role of the Federal Aviation Administration FAA Reference Material (FAA) in aviation. For the new student, this includes The reference materials described below, as revised, can be introducing him or her to the parts and subparts of 14 CFR that used by the CFI to assemble a handout for the student. An relate to flight training and pilot certification. To be included example of such a handout can be found in Appendix A. are pertinent handbooks, the PTS, and any references the CFI determines to be valuable to the student pilot learning • Pilot’s Handbook of Aeronautical Knowledge experience. For transitioning pilots, the PTS for the helicopter (FAA-H-8083-25)—provides essential knowledge for is a key reference. The student should also be introduced to the pilots as they progress through pilot training. Useful Knowledge Test Guides that can be found at www.faa.gov. to beginning pilots, as well as those pursuing more advanced certificates. An online session at the FAA website provides the CFI with an opportunity to introduce the new student and/or • Helicopter Flying Handbook (FAA-H-8083-21)— transitioning pilot to the many resources now available designed as a technical manual for applicants who around the clock. The site has easy-to-access handbooks, are preparing for their private, commercial, or flight regulations, standards, manuals, references, and even online instructor pilot certificates with a helicopter class courses. With the advent of the Integrated Airman Certificate rating. The handbook contains detailed coverage of and/or Rating Application (IACRA), the FAA can process aerodynamics, flight controls, systems, performance, airman certification documents via the Internet, interfacing flight maneuvers, emergencies, and ADM specific to with multiple FAA national databases to validate data helicopter flight, which makes it a valuable training aid. Helicopters are rotorcraft as are gyroplanes. 1-3

Gyroplanes and helicopters are the two classes of to helicopter operations. The AIM also provides the aircraft in the rotorcraft category. Therefore, to aviation community with basic flight information and differentiate between the classes of aircraft with Air Traffic Control (ATC) procedures for use in the different skill requirements, the FAA issues rotorcraft National Air Space (NAS) of the United States. It also helicopter ratings or rotorcraft gyroplane ratings. contains items of interest to pilots concerning health/ medical facts, factors affecting flight safety, etc. • Instrument Flying Handbook (FAA-H-8083-15)— designed for use by instrument flight instructors • Airport/Facility Directory—containing information and pilots preparing for instrument rating tests, this on public and joint use airports, communications, handbook is a valuable training aid for CFIs as it navigation aids, instrument landing systems, very includes basic reference material for knowledge high frequency (VHF) omnirange navigation system testing and instrument flight training. [Figure 1-4] (VOR) receiver checkpoints, preferred routes, Automated Flight Service Station (AFSS)/Weather Service telephone numbers, Air Route Traffic Control Center (ARTCC) frequencies, part-time surface areas, and various other pertinent special notices essential to air navigation, the directory is now available in digital format at www.faa.gov. • Practical Test Standards—the Rotorcraft (Helicopter and Gyroplane) PTS establishes the standards for pilot certification practical tests for the rotorcraft category, helicopter, and gyroplane classes. FAA inspectors and designated pilot examiners (DPEs) conduct practical tests in compliance with these standards. Flight instructors and applicants should find these standards helpful during training and when preparing for the practical test. More detailed information can be found at www.faa.gov. Refer the new student to page 3 of the PTS which provides a list of references used to compile the standards under which he or she is tested. This list identifies the publications that describe the various tasks that need to be mastered prior to the test. While explaining the PTS, be sure to review the Rotorcraft Practical Test Prerequisites. Figure 1-4. The Instrument Flying Handbook is one of many training An applicant for the Rotorcraft Practical Test is required by aids provided by the FAA Airman Testing Standards Branch. 14 CFR part 61 to: • Risk Management Handbook (FAA-H-8083-2)— 1. Be able to read, speak, write, and understand the provides tools to help pilots determine and assess each English language. (If there is a doubt, use Advisory situation for the safest possible flight with the least Circular (AC) 60-28, English Language Skill amount of risk. This handbook presents methods pilots Standards.) can use to manage the workloads associated with each phase of flight, resulting in a safer, more enjoyable, 2. Have passed the appropriate pilot knowledge test since and less stressful experience for both themselves and the beginning of the 24th month before the month in their passengers. which the practical test is completed. • Advanced Avionics Handbook (FAA-H-8083-6)— 3. Have satisfactorily accomplished the required training provides general aviation users with comprehensive and obtained the aeronautical experience prescribed. information on the advanced avionics equipment available in technically advanced aircraft. 4. Possess a current Medical Certificate. • Aeronautical Information Manual (AIM)—Chapter 5. Have an endorsement from an authorized instructor 10 of the AIM includes items that specifically pertain certifying that the applicant has received and logged training time within 60 days preceding the date of application. 1-4

6. Also have an endorsement certifying that the applicant Role of the Certificated Flight Instructor has demonstrated satisfactory knowledge of the (CFI) subject areas in which the applicant was deficient on the airman knowledge test. The FAA places full responsibility for student flight training on the shoulders of the CFI, who is the cornerstone of aviation Role of the Examiner safety. It is the job of the flight instructor to train the student in all the knowledge areas and teach the skills necessary for The subject of the PTS also offers the CFI an opportunity the student to operate safely and competently as a certificated to discuss the role of the examiner who plays an important pilot in the NAS. The training is not limited to airmanship role in the FAA’s mission of promoting aviation safety skills, but includes pilot judgment and decision-making and by administering FAA practical tests for pilot and flight good operating practices. instructor certificates and associated ratings. To satisfy the need for pilot testing and certification services, the A pilot training program depends on the quality of the ground FAA delegates certain of these responsibilities to private and flight instruction the student receives. A competent individuals who are not FAA employees. instructor must possess a thorough understanding of the learning process, knowledge of the fundamentals of teaching, Appointed in accordance with 14 CFR section 183.23, and the ability to communicate effectively with the student. a designated pilot examiner (DPE) is an individual who He or she uses a syllabus and teaching style that embodies meets the qualification requirements of the Pilot Examiner’s the “building block” method of instruction. In this method, Handbook, Order 8710.3, and who: the student progresses from the unknown to the known via a course of instruction laid out in such a way that each new • Is technically qualified. maneuver embodies the principles involved in the performance of maneuvers previously learned. Thus, with the introduction • Holds all pertinent category, class, and type ratings of each new subject, the student not only learns a new principle for each aircraft related to their designation. or technique, but also broadens his or her application of those principles or techniques previously learned. • Meets requirements of 14 CFR part 61, sections 61.56, 61.57, and 61.58, as appropriate. Insistence on correct techniques and procedures from the beginning of training by the CFI ensures the student develops • Is current and qualified to act as pilot in command proper habit patterns. Any deficiencies in maneuvers or (PIC) of each aircraft for which they are authorized. techniques must immediately be emphasized and corrected. A CFI serves as a role model for the student who observes • Maintains at least a third-class medical certificate if the flying habits of his or her flight instructor during flight required. instruction, as well as when the instructor conducts other pilot operations. Thus, the CFI becomes a model of flying • Maintains a current flight instructor certificate, if proficiency for the student who, consciously or unconsciously, required. attempts to imitate the instructor. The CFI’s advocacy and description of safety practices mean little to a student if the Designated to perform specific pilot certification tasks instructor does not demonstrate them consistently. For this on behalf of the FAA, a DPE may charge a reasonable reason, CFIs must observe recognized safety practices, as fee. Generally, a DPE’s authority is limited to accepting well as regulations during all flight operations. applications and conducting practical tests leading to the issuance of specific pilot certificates and/or ratings. The An appropriately rated CFI is responsible for training the majority of FAA practical tests at the private and commercial pilot applicant to acceptable standards in all subject matter pilot level are administered by DPEs, following FAA areas, procedures, and maneuvers included in the tasks provided test standards. within the appropriate PTS. Because of the impact of their teaching activities in developing safe, proficient pilots, flight DPE candidates must have good industry reputations for instructors should exhibit a high level of knowledge, skill, and professionalism, integrity, a demonstrated willingness the ability to impart that knowledge and skill to students. to serve the public, and adhere to FAA policies and procedures in certification matters. The FAA expects the DPE to administer practical tests with the same degree of professionalism, using the same methods, procedures, and standards as an FAA aviation safety inspector (ASI). 1-5

Additionally, the flight instructor must certify that the set up the helicopter for a slight right quartering headwind applicant is able to perform safely as a pilot and is to compensate for translating tendencies, then allowed competent to pass the required practical test. Throughout the the student to manipulate the controls. During hover, the applicant’s training, the CFI is responsible for emphasizing helicopter exhibited pendulum action that is common for the performance of effective visual scanning, collision new students learning to hover. During one of the right lateral avoidance, and runway incursion avoidance procedures. oscillations, the helicopter unexpectedly lost altitude. The right skid contacted the ground, and the helicopter rolled Anyone who enrolls in a pilot training program commits over onto its right side. Within seconds, it ignited. Both pilots considerable time, effort, and expense to earn a pilot exited immediately. certificate. Many times an individual judges the effectiveness of the flight instructor and the success of the pilot training Since the helicopter and engine had no mechanical failures program based on his or her ability to pass the requisite FAA or malfunctions during the flight, the accident might have practical test. A truly professional flight instructor stresses to been prevented by: the student that practical tests are a sampling of pilot ability compressed into a short period of time. The goal of a CFI is • Maintaining a proper skid height during instruction at to train the “total” pilot. all times. Flight Safety Practices • Stopping the lateral and aft movement sooner. A major component of the FAA’s mission is to improve • Restricting hovering flight to later lessons after the the nation’s aviation safety record by conveying safety student has gained some insight and appreciation principles and practices through training, outreach, and of the control responsiveness and sensitivity of the education. The goal to reduce the number of accidents in helicopter. the ever increasingly populated airways means safe flight practices are an important element of flight instruction. It is The CFI also should have stayed on the controls longer to the CFI’s responsibility to incorporate flight safety into the give the student more time to become familiar with them. program of training. The CFI violated the building block principle of simple to complex. The student had no experience to build upon. Do not become complacent about safety while instructing. Helicopter students learn best by beginning in the air where The CFI must always be vigilant about safety and must instill there is a greater margin of error and then learning to fly a safety-first attitude in the student. According to statistics closer to the ground. from Helicopter Association International’s (HAI) Five-Year Comparative U.S. Civil Helicopter Safety Trends, the ratio Accident data at the NTSB offer CFIs excellent scenario of instructional/training-related accidents to total accidents in material for safety discussions. Updated daily and located at the United States has increased more than 18 percent between www.ntsb.gov, descriptions of more than 140,000 aviation January 1, 2002, and December 31, 2006. Interestingly accidents can be searched by a variety of factors, such as enough though, the total number of helicopter flight hours has date or aircraft category. increased by 37 percent, while the accident rate per 100,000 flight hours has drastically decreased—by 42 percent in the Helicopter Hazards same time period. The entire U.S. Civil Helicopter Safety Statistic - Summary Report can be found at www.rotor.com. During the entire training program, CFIs should emphasize safe operation of the aircraft. The student must be introduced Accidents happen quickly during flight instruction, as to and completely understand the flight characteristics of the this recent National Transportation Safety Board (NTSB) type helicopter being flown. Loss of tail rotor effectiveness accident report reveals: (LTE), dynamic rollover (DRO), and the meaning of and how to interpret the height velocity diagram are three topics During a training flight, a helicopter collided with terrain. of discussion for continuous review. By virtue of its many Weather was visual flight rules (VFR) with no flight plan filed. moving parts, the helicopter presents numerous hazards. This was the CFI’s first instructional flight with this student. [Figure 1-5] It is the responsibility of the CFI to teach safe They conducted the preflight inspection of the helicopter operating practices in and around the aircraft. together, started up, and departed for the practice area. A CFI should draw to the attention of the student the hazards Once the student had a general understanding of the controls, that include, but are not limited to the following: they did an approach that terminated in a hover. The CFI • For single rotor helicopters, students should be taught from the beginning that it is preferred to approach 1-6

SAFETY AROUND HELICOPTERS Approaching or Leaving a Helicopter Do not approach or leave without the pilot’s visual PROHIBITED acknowledgement. Keep in pilot’s field of vision at all times. Observe helicopter safety zones (see diagram at right). PROHIBITED On sloping ground, always approach or leave on the downslope side for maximum rotor clearance. PREFERRED If blinded by swirling dust or grit, STOP—crouch lower, or sit down and await assistance. ACCEPTABLE PREFERRED If disembarking while helicopter is at the hover, get out and Proceed in a crouching manner for extra rotor clearance. off in a smooth unhurried manner. Hold onto hat unless chin straps are used. Never, reach up or chase after a hat or other articles that blow away. Do not approach or leave a helicopter when the engine and Carry tools, etc., horizontally below waist level—never upright rotors are running down or starting up.* or on the shoulder. *It is common in some operations to leave a running helicopter to refuel or load passengers or cargo. If doing so, the controls must be frictioned down to prevent movement from the selected position and usually, the engine is brought back to the idle setting. The pilot must be extremely carfeul in exiting and entering the cockpit so as to not move the controls. The pilot should ensure that their headset is unplugged or properly stowed so as to remain clear of the flight controls. Seatbelts and doors should not be left flapping in the rotor wash. Figure 1-5. Safe operating procedures in and around the helicopter. 1-7

and exit the helicopter from the sides but that the be caught on any fasteners or sharp objects. Loose forward quarter is acceptable. If approaching or clothing should be secured, and objects in pockets exiting a helicopter that is on a slope, always exit on should be removed if the pockets cannot be fastened. the downward side to avoid contact with the rotor blades. Limited access to the near aft portion of the In hover flight, the CFI should emphasize the hazards that fuselage is acceptable for some helicopters, such as rotor wash presents to persons or light aircraft nearby. Dust the BO-105 and BK-117, in which the tail rotor has and debris cause eye injuries and vortices damage light been elevated and loading is in the rear of the fuselage. aircraft. A tail rotor is another source of significant hazard CFIs should advise students to always consult with because it is out of sight of the pilot. Instructors should ensure the pilot or trained personnel before going aft of the the student is aware of the requirement to keep the tail rotor cockpit doors. This instills in the students the preferred area cleared. Hazards such as those listed above are but a few direction to enter and exit the rotor disk area so the of the hazards unique to the helicopter. The observant CFI pilot can maintain eye contact with personnel around identifies potential hazards during the lesson, corrects the the aircraft. During preflight, the CFI should teach deficiency immediately with an explanation, and develops students to do a proper walk-around before moving them as teaching points. any control surfaces to ensure that nothing is in the way of the main or tail rotor blades. Instructional Hazards • Always avoid the tail rotor by approaching from the Flying a helicopter offers a different set of physical and sides. The rotor disk should be tipped so the students mental challenges for a student. The stress of learning how understand just how low the main rotor blades may to fly is coupled with the physical demands of flying the dip in winds and as a result of exaggerated control helicopter. The constant vibration of the aircraft, as well movements. as the continually need to make control inputs to “fly” • Hands and fingers can be pinched by rotor hubs and the aircraft, make helicopter flight a more physically and hinges during preflight and postflight inspections. mentally strenuous type of flying. The vibration, noise, and stress can lead to fatigue, which can have a detrimental effect • Main and tail rotor blades pose significant hazards upon the ability of the student not only to fly a helicopter but for those unaccustomed to being around helicopters to absorb instruction. To combat this hazard, limit the length during ground operations. of the lesson to less than an hour until the student becomes • Any moving blade is dangerous and can cause injury accustomed to the demands of this type of flying. For further or damage while under power or during the start up discussion of medical factors associated with flying, refer to and coast down periods after engine power has been the Pilot’s Handbook of Aeronautical Knowledge. removed. As shown in Figure 1-6, the CFI must remain vigilant when the student has control of the helicopter because the • Wind or a control input can easily cause slow moving student’s knee may get in the way of the cyclic movement. blades to droop or flex, reducing clearance for people The student’s size cannot be changed, but it is the CFI’s standing underneath the rotor disk. • If the helicopter must be moved from the hangar, responsibility to teach the student to be aware of how their students should be cautioned on the hazards of having size may affect the flight controls input. a piece of machinery raised off the surface and the correct methods of raising and lowering the aircraft. The instructor should always ensure that all of the flight Since helicopters may be taller than an equal size controls are unencumbered. Students are so focused on airplane; the student should be taught to ensure plenty the task at hand when learning to fly and often times will of vertical clearance for the aircraft as it is moved. Trip unknowingly obstruct the flight controls. For example, hazards, such as ground wires, should be explained as to water bottles, clothing and cameras can get stuck under the requirements, storage, and attachment at end of flights. collective levers preventing movement, or anti-torque pedals • The movement of the helicopter for flight should can get blocked from movement by the students boot or shoe. include preplanning to prevent the hangar from filling with grass, dirt, and excessive wind in the facility. The Another potential instructional hazard stems from the ability direction of the wind and airflow around the building of helicopter rotor blades to strike the terrain or objects in should be considered before selecting a takeoff point a 360° arc. This unique capability of the helicopter must be stressed when teaching a student who is transitioning from for the helicopter. fixed-wing aircraft. A fixed-wing pilot is accustomed only • Jewelry, especially rings, should be removed before to the idea that one wing will hit if the aircraft is banked too preflight and postflight to ensure that they will not 1-8

Figure 1-6. Robinson Helicopter R-22. far. If teaching someone who is transitioning from airplanes, the CFI needs to stress to the student the speed of the rotor and its close proximity to the ground. Collision Avoidance While pilots often believe that having a CFI on board minimizes the possibility of a midair collision (MAC), FAA research reveals that flight instructors were on board the aircraft in 37 percent of the accidents studied. From a collision perspective, flight training is one of the most dangerous missions—an especially frightening fact, considering that flight instructors comprise less than 10 percent of the pilot population. See and Avoid As discussed in the Aviation Instructor’s Handbook, the CFI must ensure from the start of flight training that the student develops the habit of maintaining airspace surveillance at all times. [Figure 1-7] If a student believes the instructor assumes all responsibility for scanning and collision avoidance procedures, he or she will not develop the habit of maintaining the constant vigilance essential to safety. Establish scan areas and communication practices for keeping the aircraft cleared as outlined in the AIM, paragraphs 4-4-15 and 8-8-6c. For example, “Clear left? Cleared left. Turning left.” should be verbalized in conjunction with the actual scanning. In addition to clearing left and right, a helicopter pilot must also clear directly above and below since the helicopter has the ability of climbing and descending Figure 1-7. Collision avoidance, both in the air and on the ground, is one of the most basic responsibilities of a pilot flying in visual conditions. 1-9

vertically. This ability has resulted in helicopters climbing You have the directly into overhead hangar doors and power lines. Any flight controls. observed tendency of a student to enter flight maneuvers without first making a careful check for other air traffic must I have the be corrected immediately. In addition to the statistic quoted flight controls. above, recent studies of midair collisions determined that: You have the • Most of the aircraft involved in collisions are engaged flight controls. in recreational flying, and not on any type of flight plan. Figure 1-8. There should never been any doubt about who is flying • Most midair collisions occur in VFR weather the helicopter. conditions during weekend daylight hours. a proven procedure and one that is strongly recommended. • The vast majority of accidents occurred at or near During this procedure, a visual check is recommended to see nontowered airports and at altitudes below 1,000 feet. that the other person actually has the flight controls. When returning the controls to the instructor, the student should • Pilots of all experience levels were involved in midair follow the same procedure the instructor used when giving collisions, from pilots on their first solo ride to 20,000- control to the student. There should never be any doubt as hour veterans. to who is flying the aircraft. • Most collisions occur in daylight with visibility greater CFIs should always guard the controls and be prepared to take than three miles. control of the aircraft. When necessary, the instructor should take the controls and calmly announce, “I have the flight It is imperative to introduce 14 CFR section 91.113, Right- controls.” If an instructor allows a student to remain on the of-Way Rules: Except Water Operations,” for the “see and controls, the instructor may not have full and effective control avoid” concept immediately to the student. Practice the “see of the aircraft. Anxious students can be incredibly strong and and avoid” concept at all times regardless of whether the usually exhibit reactions inappropriate to the situation. If a training is conducted under VFR or instrument flight rules recovery is necessary, there is absolutely nothing to be gained (IFR). A CFI and student can review the FAA’s suggestions by having the student on the controls and needing to fight for for how to contribute to professional flying and reduce the control of the aircraft. Students should never be allowed to odds of being involved in a midair collision, at www.faa.gov. exceed the flight instructor’s limits. Flight instructors should Other references that contain collision avoidance information not exceed their own ability to perceive a problem, decide for both the CFI and student are AC 90-48, Pilot’s Role in upon a course of action, and physically react within their Collision Avoidance; FAA-H-8083-25, Pilot’s Handbook of ability to fly the aircraft. Aeronautical Knowledge; and the Aeronautical Information Manual (AIM) (all as revised) located online at www.faa.gov. Single-Pilot Resource Management (SRM) Positive Exchange of Flight Controls Incident/accident statistics indicate a need to place additional According to data presented at the 2005 International emphasis on the exchange of control of an aircraft by Helicopter Safety Symposium, the helicopter accident rate pilots. Numerous accidents have occurred due to a lack of is 30 percent higher than the general aviation (GA) accident communication or misunderstanding as to who actually had rate. Reducing this rate is an industry wide goal and the CFI control of the aircraft, particularly between students and plays an important role in reaching it by stressing single-pilot flight instructors. Establishing the following procedure during resource management (SRM) and risk management during initial training ensures the formation of a habit pattern that flight training. should stay with students throughout their flying careers. They are more likely to relinquish control willingly and As discussed in the Aviation Instructor’s Handbook and the promptly when instructed to do so during flight training. Pilot’s Handbook of Aeronautical Knowledge, SRM is the During flight training, there must always be a clear understanding between the student and the flight instructor of who has control of the aircraft. [Figure 1-8] Prior to flight, a briefing should be conducted that includes the procedure for the exchange of flight controls. A positive three-step process in the exchange of flight controls between pilots is 1-10

art and science of managing all resources (both onboard the management is to provide a proper balance between risk and aircraft and from outside sources) available to a single pilot opportunity. Two elements define risk management: hazard (prior and during flight) to ensure the successful outcome and risk. Hazard is a real or perceived condition, event, or of the flight. SRM grew out of the airline industry’s crew circumstance that a pilot encounters. Risk is how the pilot resource management (CRM) training for flight crews that views the potential impact of the hazard. was launched in an effort to reduce human factors-related aircraft accidents. SRM is the effective use of all available Risk management is the method used to control, eliminate, resources: human, hardware, and information to ensure a safe or reduce the hazard to an acceptable level. The individual flight. The CFI must keep in mind that SRM is not a single pilot is unique to risk management. An acceptable level of task; it is a set of skill competencies that must be evident in risk to one pilot may not necessarily be the same to another all tasks. Aviation resource management charges the flight pilot. Unfortunately in many cases, the pilot perceives that instructor with the responsibility of teaching the student a his or her level of risk acceptability is actually greater than safety mindset that enhances his or her decision-making skills. their capability, thereby taking on risk that is dangerous. SRM depends upon teaching the student higher order thinking For example, prior to entering a helicopter, the CFI must skills (HOTS) as discussed in Chapter 2 of the Aviation establish his or her own limitations. How far is the CFI Instructor’s Handbook. HOTS are taught from simple to willing to allow the student to drift during a hover? Once complex and from concrete to abstract. To teach HOTS personal limitations are established, the CFI must fly within effectively involves strategies and methods that include: them. The CFI should always ensure that the helicopter is never allowed to depart the instructor’s comfort zone and • Using problem-based learning (PBL) instruction, maneuvering limitations. In reality, the instructor is observing the maneuvering of the helicopter and monitoring the control • Authentic problems, movements by sight or feel. The helicopter instructor has to be very familiar with that particular helicopter and it’s • Student-centered learning, responses to control inputs and winds, especially at a hover with a wing with an airspeed of 400+ knots flying while at • Active learning, 3 feet landing gear height above the surface. A split second delay in correcting an errant control input can be disastrous. • Cooperative learning, and • Customized instruction to meet the individual learner’s needs. These strategies engage the student in some form of mental References and resources for risk management include: activity, have the student examine that mental activity and select the best solution, and challenge the student to explore • Pilot’s Handbook of Aeronautical Knowledge, other ways to accomplish the task or the problem. FAA-H-8083-25 Student understanding of risk management and judgment • Pilot risk management brochures located at www.faa. is enhanced when the instructor includes the student in all gov (brochures include tips for teaching practical risk preflight practices and procedures, as the instructor shares management) [Figure 1-9] the logic behind decisions whether to fly or not to fly. If the instructor uses the performance charts every time before • Risk Management Handbook, FAA-H-8083-2 flying to ensure sufficient power, control authority, and lift is available, then the student will probably acquire that habit. Since the DPE evaluates the applicant’s ability to use good If the instructor always prompts the student to call for a ADM procedures in order to evaluate risks throughout weather, NOTAMS, and TFR briefing, then the student will the practical test, it is important the CFI incorporates risk learn proper preflight planning techniques. If the instructor management into the flight lessons as soon as possible. The determines what the student wants to be able to do with the scenarios should be realistic and within the capabilities of helicopter, then the instructor can makes plans to ensure the helicopter used for the practical test. that the hazards inherent to those operations are covered completely and emphasized during training. To teach risk management, CFIs must understand system safety flight training occurs in three phases. First, there Risk Management are the traditional aircraft control maneuvers. In order to apply critical thinking skills, the student must first have a The FAA is committed to reducing the number of helicopter high degree of confidence in their ability to fly the aircraft. accidents and promoting risk management as an important Basic airmanship skill is the priority during this phase of component of flight training. The objective of risk flight training. The CFI accepts the responsibility of risk management until the student is able to accept more tasking. 1-11

Figure 1-9. Brochure available from the FAA website for teaching practical risk management. In the second phase, the CFI teaches the student how In the third phase, as the student is completing the course of to identify hazards, manage risk, and use all available training, the instructor should begin exposing the student to resources to make each flight as safe as possible. This can practical scenarios of helicopter flight and enable the student be accomplished through scenarios that emphasize the skill to discern the hazards associated with each profile. Using sets being taught. For example, the CFI could inform the the “simple to complex” method at all times, the student is student that they were going to do some photography in introduced to scenarios demanding focus on several safety- the mountains for a survey. The instructor could give the of-flight issues. [Figure 1-10] student two temperatures and one elevation for the areas. Then, the instructor would assist the student in reviewing The CFI must present the subject of risk management as it the performance charts for the two temperatures and relates to helicopter operations for the level of instruction have the student determine the differences in helicopter being presented. For example, a new helicopter student performance with those temperatures and how to determine has different requirements from those of a prospective any maneuvering restrictions from those temperatures. commercial Emergency Medical Services (EMS) pilot. “Does the lack of OGE hover restrict anything?” could be one question. Then hopefully, the CFI and student would fly Chapter Summary up to some point for the student to have a safe and real-life experience of the difference in aircraft performance in higher This chapter introduced the purpose of flight training, temperatures and higher density altitudes. resources available to the CFI, a brief overview of flight safety practices, and hazards unique to helicopter flying. 1-12

Documentation System Safety Process Risk Management System/Process Review Modify System/Process Define Objectives System Descriptions Hazard Identification: Identify Hazards and Consequences Risk Analysis: Analyze Hazards and Identify Risks Risk Assessment: Consolidate and Prioritize Risks Decision-Making: Develop an Action Plan Validation of Control: Evaluate Results for Further Action Risk Management Figure 1-10. An example of a system safety process an instructor could use in flight training. 1-13

1-14

IChnaptterr2oduction to the Helicopter Introduction The objective of the first flight lesson is to determine the student’s motivation and goals and introduce the student to: • Training procedures • The helicopter • Local flying area and prominent landmarks • The relationship between control inputs and aircraft attitude 2-1

Training Procedures • Emergency egress. The introduction to training procedures offers the certificated flight instructor (CFI) an opportunity to better ascertain • Foreign object damage (FOD) hazards associated with the student’s experience and background, which influence items, such as hats, jackets, and loose paperwork. training. At this time, the CFI explains the general safety procedures, lay out of the school, the course syllabus and how • Seat belt use at all times during flight. it is used. This includes how, when, and where instruction will take place. The CFI also discusses the role of preflight • Proper wear and use of the headset. and postflight briefings in the training program, as well as how he or she monitors the student’s progress. Additionally, • Proper sitting posture and position of the hands and the introduction to training should be used to determine the feet. student’s motivation for flight training and learn what their goals are. By understanding what the student would like to • Positive exchange of controls procedures and gain through flight training, the CFI will be better prepared acknowledgments. to tailor their training plan to the needs of the student. • The see-and-avoid concept. Introduction to the Helicopter Walking the student through a preflight provides an excellent • The clock method of reporting aircraft and other opportunity to introduce or review the main components hazards to flight to the other crewmember. of the helicopter. [Figure 2-1] Refer the student to the Helicopter Flying Handbook for in-depth information on • The need for clothing suitable for the location and the rotor systems, landing gear, and flight controls. During weather. It is always good practice to have sufficient the discussion, the CFI should demonstrate how to enter and clothing for walking back to the starting point. exit the helicopter properly while the rotors are turning. This Helicopters can readily take a pilot far beyond is also a good time to explain or review: populated areas. The pilot should always have enough resources to survive or to wait for a repair crew to • General helicopter hazards, such as main and tail rotor arrive, in case of emergency. (Please refer to Chapter blades. A simple demonstration of how low main rotor 12, Helicopter Emergencies.) blades can droop is possible by manually pulling down on the tip of a static blade. In aircraft equipped with • Suitable eye protection, such as good sunglasses retractable droop stops, the CFI must explain that to protect the eyes from harmful rays that produce actual droop can be greater once the stops retract with cataracts in later years. Helicopters admit much greater rotor revolutions per minute (rpm). Ensure that more sunlight than almost any other aircraft, due all demonstrations comply with restrictions found in to the bigger bubble or cockpit plexiglas area and the appropriate rotorcraft flight manual. chin window areas. Additionally, many helicopters fly with the doors off in warmer climates, thereby Figure 2-1. A CFI provides an overview of the helicopter to exposing the student’s eyes to much more radiation. introduce the main components and discuss how to enter and exit a helicopter properly. • Seat and pedal adjustment in the helicopter to achieve full control travel. 2-2 • Headset and commonly used noise-canceling microphone function, so that the headset and microphone can be properly fitted and adjusted. The student should know how to adjust the volume of the headset and be able to understand the instructor and radios through the headset. If a voice-activated intercom is installed, the student should be taught what the squelch control function does and how to adjust it when necessary. Headsets not utilized should be disconnected and stowed away to prevent unwanted noise and reduce the risk of FOD. Also, loose items such as seatbelts, bags, jackets, hats, and flight publications should be stowed. • Controls and buttons located on the cyclic and collective. Most of this preflight instruction should be done in as quiet a location as possible before engine start. After engine start, student perceptions will probably be overloaded quickly with new

experiences and sensations from their first helicopter to comprehend, not just remember and perform by rote flight. Effective instruction would have the ground memorization. instructor bringing the class out to the helicopter after every lesson to have them locate, examine, and Introduction to Flying describe the function of each part described in that For the first flight, the instructor should give the student just lesson. The students should be able to explain the enough flight experience to make the student want to come relationship between a component of the helicopter back for more. During the first flight, the CFI should allow the and the aerodynamics requiring that component. student to fly the aircraft and have fun doing it. An enjoyable introductory flight builds student motivation and the student The importance of good prebriefings can never be overstated. will be more ready to learn. Solo flight comes after more In almost every case, if the student does not learn from flight experience, so there is plenty of time for the student the briefing what is expected and the contents of the flight to learn local landmarks. [Figure 2-2] This flight should be lesson for that day before going to the helicopter, then that an introduction to flying itself and should follow the pattern student will not learn after getting into and starting the of learning simple tasks before more complex tasks. The helicopter. Instructors forget that the new student pilot is student should learn to fly first, and then learn where to fly. constantly barraged by new information. Newly experiencing the sights, sounds, vibrations, and other sensory inputs of helicopter flight, the beginning student has great difficulty understanding and remembering what the instructor says. If the instructor merely reinforces what the student learned in the classroom, the student is more likely to recall the instructions and procedures for the maneuvers amid the new experiences. Likewise, during the prebriefing, the student should be Figure 2-2. During an introductory flight, a student pilot receives introduced to the flying area. The time required for a review the first helicopter flight experience while being shown the general of the chart to be used depends on the experience level of the functions of the controls and instruments and is also introduced to student and when charts and maps were taught during the the local landmarks and the layout of the airfield. training. The instructor should also remember that the student may not remember as well if the student is always on the flight controls. The instructor may need to relieve the student of the flight controls for a few moments near each boundary marker or checkpoint for the student to have time to fully absorb the view and relate the sight to the chart or map being used. If the student has airplane experience, the instructor should The CFI must show the student that flying can be fun, and be aware of negative transfer of airplane skills to helicopter then introduce the student to the local flying area. During this flying. The first flight should set the stage for the remainder flight, seat the student at the pilot’s seat. (Seat the new student of the flight course. A shorter flight is always better than a at the copilot’s seat for the first few flights if access to engine long flight. If the student becomes warm or hot, the likelihood starting or flight control friction is not easily accessible from of airsickness is greater. Some students have an aversion the copilot’s seat.) Explain the general function of the controls to heights, which can be overcome by determination and and instruments. Demonstrate adjustment of the controls gradual exposure. for comfort and safety, as applicable to the make and model of helicopter being flown. Relate this flight to the student’s The instructor has the duty always to give the student flying background and level of experience. For example, a just enough—just enough encouragement, or just enough new student’s introductory flight can also be used to discuss challenge for that stage of training, or just enough critique— basic air traffic control (ATC) functions and procedures. for the student to learn but not to discourage. The instructor should always have enough understanding of the student’s A brief “hands on” for the student during cruising flight progress to discuss the student’s problems and explain how helps the CFI further evaluate the student’s level of ability. or why the error is occurring and what corrective or different If at all possible, the first flight or at least the first portion of action to take to have a better outcome. Especially on the the first flight should be conducted in a calmer environment, ground, the instructor should always strive for the student such as in the morning or at a higher altitude, so the student 2-3

has a chance to experience the helicopter flight without the After the debriefing, most successful instructors begin to turbulence that is often confusing to the student. brief the student on the contents of the next day’s training flight. This allows: This flight also provides the CFI with an opportunity to evaluate the student’s attitude, tolerance, and temperament. 1. The student time between flights to study and think The student should enjoy this first trip, creating a positive about the next maneuver to learn at their own pace. foundation for the rest of the course. Explain that procedures that seem complicated at this time become easier with more 2. The student to recall questions from the current flight exposure and training. about a specific point during the flight. Try to avoid confusing the student by presenting too much 3. The student to formulate questions concerning detailed information at this early stage in training. As practices or procedures for the instructor to address discussed in the Aviation Instructor’s Handbook, students before the next flight. tend to acquire and memorize facts when exposed to a new topic. As learning progresses, they begin to organize their 4. The instructor to relate the current flight to the knowledge to formulate an understanding of the things they upcoming flight’s goals and maneuvers to further have memorized. Progressing further still, students learn to the student’s understanding of the relationship of the use the knowledge they have compiled to solve problems procedures. and make decisions. Encourage and praise such behavior whenever students exhibit the pilot in command (PIC) Instructor Tips input. Keep in mind that student performance should not be criticized or corrected at this stage; explain in general terms • For the airplane pilot transitioning to helicopters, what occurs during flight to clarify student’s understanding. remind the student that a helicopter is very different from an airplane and much negative transfer is possible In the early stages of flight training, the traditional lesson if they do not continually remind themselves of which plan (see the Aviation Instructor’s Handbook) provides aircraft that they are flying at the time. Helicopters the CFI with a teaching delivery method more in tune with are designed and built to be controllable. Airplanes the student’s level of knowledge. Scenario-based training are designed and built to be stable. Helicopter flight (SBT) works better with learners who have mastered the controls are considerably more sensitive than those basic knowledge needed to make more advanced decisions. in an airplane, which can be difficult for a former The samples used in the early chapters utilize the traditional airplane pilot to adjust to. CFI’s must also explain lesson plan. the aerodynamic effects that must be controlled by the helicopter pilot due to the main rotors’ blade tip The most important lesson for helicopter pilots to learn is to speed. [Figure 2-3] The Helicopter Flying Handbook be wary. As training progresses, the instructor can incorporate is a good reference for detailed explanations on the discussions of documented helicopter accidents related to the calculations of the main rotors’ blade tip speeds and lesson of the day. The instructor can offer techniques and the magnitude of the aerodynamic effects that must procedures that would prevent that type of incident from be controlled by the helicopter pilot. happening. While it is important to relate some of these stories to student pilots, the instructor should avoid too many • Avoid sudden or violent maneuvers that might make accident discussions early in the training as they may instill a newcomer to flying nervous. Emphasize how little fear in students that may not understand the details. Respect movement is required on the cyclic and collective for the dangers in aviation can aid a student’s progression, controls. This is critical for prior airplane pilots and but fear acts as a barrier to learning. can be demonstrated by calculating and explaining the blade tip speed to emphasize the magnitude of the Instructors in the debriefing after the flight should always aerodynamic effects controlled by a helicopter pilot. discuss what was satisfactory and then discuss what Introduce the pedal requirement immediately with improvements the student could make and, even more short quick inputs rather than slow and long inputs. important, how to make improvements. It does not help the Demonstrate and point out to the student which part student to say the flight was unsatisfactory that day if the of the body should be used and are necessary in order instructor cannot describe in detail how the student could to achieve the proper input. correct any responses or maneuvers. • Monitor the student pilot’s hand grip pressure on the flight controls, foot position on the pedals, body posture, and eyes regularly for clues of nervousness, lack of progress, improper reaction to the situation, and situational unawareness. 2-4

Introduction to the Helicopter Objective The purpose of this lesson is to introduce the student to rotary-wing flight. The student demonstrates a basic knowledge of the main components, safe helicopter entry and exit, and use of flight controls in cruise flight. Content 1. Preflight Discussion a. Discuss lesson objective and completion standards b. Normal checklist procedures coupled with introductory material c. Weather analysis 2. Review 3. Instructor Actions a. Preflight used as introductory tool b. Short, familiarization flight 4. Student Actions a. Enters and exits helicopter safely b. Handles controls in cruising flight Postflight Discussion Preview and assign the next lesson. Assign Helicopter Flying Handbook, Chapter 1, Introduction to the Helicopter, and Chapter 2, Aerodynamics of Flight. Figure 2-3. Example of a traditional lesson plan. horizon and to relate the control inputs necessary to achieve changes in the aircraft’s attitude. On the first flight, acquaint • Always practice positive transfer of control procedures the student with the basic flight instruments, such as the rotor and acknowledgments. This is particularly important tachometer, engine tachometer, compass, airspeed indicator, in the early stages of training to instill good habits altimeter, and power gauge (manifold pressure or torque). and safety when either the student or the CFI is on Additionally, show the student how the helicopter responds the controls for a long period of time. to pedal inputs at a hover versus in forward flight, and how the power changes depending on tail rotor power demands. • Helicopters are not acrobatic in the general sense. Therefore, positive “G” loads are the normal condition. The first helicopter flight should be rewarding, and not All good helicopter pilots are smooth flyers because overwhelming or boring. If possible, one day should be the they know smooth flight is good for the machine and detailed preflight and prebriefing and the next the regular passengers/cargo. preflight and actual first flight. • Sudden or violent maneuvering is usually the precursor Another item to include on the first flight is the engine cooling for main rotor or tail rotor strikes. The helicopter pilot time, including the reasons the student sees airplanes come should always be planning the flight path to avoid to a full stop and kill the engines immediately, while the close, tight situations requiring rapid maneuvering. helicopter pilot must sit for some minutes before the engine can be shut down. Explain that a helicopter requires relatively The helicopter instructor should be relating the ongoing more power to hover taxi than an airplane requires to ground training to student plans for after they earn their certificates. taxi. Helicopters require more of their available power to This encourages learning and help students relate the training hover so the powerplant is relatively hotter and requires a to a positive personal goal. longer cool-down period. Generally, airplane engines begin The goals of the first flight should be for the student to recognize flight attitude of the helicopter relative to the 2-5

to cool during descent to landing and require little or no time to cool down after landing. Chapter Summary This chapter provided the CFI with the objectives of an introductory flight. It also set the stage for the future training sessions, leading to the development of a competent, safety conscious, and cordial pilot. 2-6

CAhaepterr3odynamics of Flight Introduction All helicopter pilots must have a basic knowledge of the aerodynamic principles that enable helicopter flight. While the principles that apply to a helicopter are the same as those that apply to other aircraft, the application of these principles is more complex due to the rotating airfoils. Chapters 2 and 3 of the Helicopter Flying Handbook (FAA-H-8083-21) and Aircraft Weight and Balance Handbook (FAA-H-8083-1), form the foundation for this chapter. As with any training, begin the presentation of new material at the student’s level of understanding. This can be determined throughout the introductory meeting with the student simply by engaging conversation about helicopters and general flight. Any previous flight experience will be apparent during preflight and while flying. Written or oral testing on the first day of flight school could deter a student from further flight training. A proficient, certificated flight instructor (CFI) should be able to determine the background and expertise of a student by careful use of the initial introductory meeting. The student’s aviation background determines when to introduce different aspects of aerodynamics. The student must have the appropriate background knowledge to comprehend the subject matter. Periodic reviews during the course of 3-1

instruction help the instructor tailor the lesson to the student’s moves through the air. Further discussion should include the comprehension and arrange the material to fit the student’s following points and examples: needs. Define new terms when first introduced. 1. Show the student a picture of an airfoil and how the The overall objective of this chapter is to help the instructor air pressure changes when the air is disrupted. A review the aerodynamics found in the Helicopter Flying picture of an airfoil is usually a small cutout or slice Handbook (FAA- 8083-21, as revised) and help the student of the entire wing or rotor blade. The instructor should understand how those effects practically affect their explain that the entire rotor blade(s) are essentially one helicopter flight. In order to control a helicopter in flight, large airfoil. the student must have the consistent ability to identify and compensate for varying aerodynamic forces in flight. 2. As airspeed increases, surface air pressure decreases accordingly and this difference in pressure around the Forces Acting on the Aircraft airfoil is directly related to the flight of an aircraft. Define and discuss the four forces acting on an aircraft in 3. As an airfoil starts moving through the air, it divides the straight-and-level and unaccelerated flight. Give examples of mass of air molecules at its leading edge. The distance how the combinations of these forces act on the airframe. over the top of the blade with the angle of attack is greater than the distance along the bottom surface of 1. Thrust—the forward force produced by a powerplant/ the rotor blade. Air molecules that pass over the top propeller or rotor. It opposes or overcomes the force must move faster than those passing under the bottom of drag. to meet at the same time along the trailing edge. The faster airflow across the top surface creates a low- 2. Drag—a rearward, retarding force caused by pressure area above the airfoil. disruption of airflow by the wing, rotor, fuselage, and other protruding objects. Drag opposes thrust and acts 4. Air pressure below the airfoil is greater than the pressure rearward parallel to the relative wind. above it and tends to push the airfoil up into the area of lower pressure. As long as air passes over the airfoil, 3. Weight—the combined load of the aircraft itself, the this condition exists. It is the difference in pressure that crew, the fuel, and the cargo or baggage. The earth’s causes lift. When air movement is fast enough over gravitational force, which creates the weight, pulls the a wing or rotor blade, the lift produced matches the aircraft downward. weight of the airfoil and its attached parts. This lift is able to support the entire aircraft. As airspeed across 4. Lift—overcomes the downward force of weight to the wing or rotor increases further, the lift exceeds the allow flight to occur and is produced by the dynamic weight of the aircraft and the aircraft rises. effect of the air acting on the airfoil and acts vertically through the center of gravity. 5. Not all of the air met by an airfoil is used in lift. Some of it creates resistance, or drag, which hinders forward Lift motion. Lift and drag increase and decrease together. A very easy way to confuse new flight students is to throw a They are affected by the airfoil’s angle of attack in lot of obscure information at them with no concrete references the air, the speed of airflow, the air density, and the or examples. Aerodynamics can be very difficult for the new shape of the airfoil or wing. student to understand because it is difficult to visualize what is happening to the rotor blades or tail rotor in flight. When Newton’s Laws of Motion teaching the student about lift and how the helicopter is able to obtain lift, the instructor must be creative and find ways Newton’s laws of motion provide the foundation for the to explain the theories, such as Bernoulli’s Principle and student’s understanding of basic aerodynamic principles. Newton’s Laws of Motion, in direct relation to the helicopter The instructor should develop multiple ways of explaining and how every flight control movement affects lift. these laws to ensure that if the student does not comprehend one explanation, the instructor has an alternate explanation Bernoulli’s Principle that relates to something that the student will understand. Instructors should introduce Bernoulli’s Principle to the Begin with relating the laws to helicopter flight, such as student in simple terms and attempt to relate the theory the requirements for lift, thrust, and power to overcome directly to the production of lift that is created from the the effects of the three laws and the energy state of the main and tail rotor blades. The discussion should begin with helicopter. If the student has a difficult time understanding Bernoulli’s initial discovery that air moving over a surface flight examples, try using an example that is more familiar, decreases air pressure on the surface, and show the student such as a car or motorcycle. This helps the student better an example of the differences in air pressure when an object understand the laws when the instructor applies it to flight. 3-2

First Law—the Law of Inertia Second Law—The Law of Acceleration A body at rest remains at rest, and a body in motion remains in motion at the same speed and in the same direction unless A change in velocity with respect to time. The force acted upon by some external force. The key point to explain is required to produce a change in motion of a body is directly that if there is no net force resulting from unbalanced forces proportional to its mass and rate of change in its velocity. acting on an object (if all the external forces cancel each other out), then the object maintains a constant velocity. If For example, for a given helicopter, acceleration would be that velocity is zero, then the object remains at rest. And, if slower when loaded to maximum gross weight than when an additional external force is applied, the velocity changes loaded to a lesser gross weight. During a normal takeoff, the because of the force. power margin available between maximum torque available and hover power can be quite small based on helicopter A helicopter in flight is a particularly good example of the weight and environmental factors. During the transition first law of motion. There are four major forces acting on an to forward flight and through effective translational lift aircraft: lift, weight, thrust, and drag. If we consider the motion airspeed, acceleration is limited until the aircraft is in smooth of an aircraft at a constant altitude, we can neglect the lift and undisturbed air and the influence of induced drag begins to weight. A cruising aircraft flies at a constant airspeed and the subside. Once the aircraft reaches its maximum endurance/ thrust exactly balances the drag of the aircraft. This is the first rate of climb airspeed, acceleration potential is increased as part sited in Newton’s first law; there is no net force on the total drag is at its lowest point. [Figure 3-1, Point E] helicopter and it travels at a constant velocity in a straight line. Now, if the pilot changes the thrust of the engine, the thrust Drag D Total drag A Parasite drag and drag are no longer in balance. If the thrust is increased, E B Profile drag the helicopter accelerates and the velocity increases. This is the second part sited in Newton’s first law; a net external force C Induced drag changes the velocity of the object. The drag of the helicopter Speed depends on the square of the velocity. So, the drag increases with increased velocity. Eventually, the new drag equals the Figure 3-1. Drag graph. new thrust level and at that point, the forces again balance out, and the acceleration stops. The helicopter continues to fly at a new constant velocity that is higher than the initial velocity. We are again back to the first part of the law with the helicopter traveling at a constant velocity. In this example, only the motion of the helicopter in a Total drag is the sum of parasite drag and induced drag as horizontal direction is explained and as the student becomes shown in Figure 3-1, Point A and C. The total drag curve comfortable with aerodynamics, further discussions should can also be referred to as the thrust required curve because include the effects of the thrust on weight and on lift. For thrust is the force acting opposite drag. At the point where example, increasing the throttle setting increases the fuel total drag [Figure 3-1, Point D] and thrust required are at a usage and decreases the weight, and the increase in velocity minimum, the lift-to-drag ratio is maximum and is referred increases the lift as well as the drag. Each of these changes to as L/DMAX. At L/DMAX, the entire airframe is at its most effect the vertical motion of the helicopter. efficient, producing the most lift for the least drag. Maximum endurance is found at L/DMAX, because thrust required and It is important to point out the role of engine power when thus fuel flow (fuel required) are at a minimum, giving explaining the law of inertia. Power is used to accelerate maximum time airborne. the helicopter, to change its velocity, and thrust is used to balance the drag when the helicopter is cruising at a constant Third Law—Action and Reaction velocity. When a helicopter is on a normal approach, the power demand is generally in the middle range and the total For every action, there is an equal and opposite reaction. The drag is at the lowest. As the aircraft decelerates to effective instructor should relate the third law to the amount of power translational lift airspeed and terminates to a hover, the applied to the rotor system and the need for the antitorque power demand is quite significant, generally the highest of or tail rotor to supply the equal and opposite reaction to the all maneuvers. An airplane makes minimal power demands at torque of the engine(s) applied to the main rotor. The rotor the termination of its approach through the flare and landing. system of a helicopter accelerates air downward, resulting in an upward thrust. A single-rotor helicopter demonstrates 3-3

this law perfectly. Consider a helicopter on floats that is performance charts include weight as one of the variables not moored to a dock. As the main rotor begins to turn and students must be aware of the importance of managing counterclockwise during aircraft start, the fuselage reacts aircraft weight to obtain optimum performance. By reducing by turning in a clockwise direction until the point at which weight, the helicopter is able to safely take off or land at the tail rotor has reached sufficient rpm to provide the thrust locations that would otherwise be impossible. necessary to counteract that force. Explain to students how maneuvers that increase the G loading Torque effect is a result of Newton’s laws and an aspect of such as steep turns, rapid flares, or pulling out of a dive create helicopter flight that a student must thoroughly understand. greater load factors and act as a multiplier of weight. The The turning of the helicopter’s main rotor blades in one load factor is the actual load on the rotor blades at any time, direction causes the helicopter to turn in the opposite divided by the normal load or gross weight. [Figure 3-3] At direction. In most helicopters, this is counteracted by the use 30° of bank, the load factor is 1G, but at 60°, it is 1.8G, an of a second rotor (tail rotor) to provide the thrust to limit the increase of 80 percent. If the weight of the helicopter is 1,600 rotation. Some helicopters use vectored air, while others use pounds, the weight supported by the rotor in a 30° bank at a a counterrotating main rotor system. All have one thing in constant altitude would be approximately 1,600 pounds. In common—a method of counteracting the torque of the main a 60° bank, it would be 2,880 pounds and in an 80° bank, rotor system. [Figure 3-2] it would be 8,000 pounds. Emphasize to students that an additional cause of large load factors is rough or turbulent 1 air. The severe vertical gusts produced by turbulence can cause a sudden increase in angle of attack (AOA), resulting in increased rotor blade loads that are resisted by the inertia of the helicopter. 2 7 2 6 1 Load factor (G units)5 43 4 3 1 Rotation direction of engine-driven main rotor 2 1 2 Torque effect 00° 10° 20° 30° 40° 50° 60° 70° 80° 90° 3 Tail rotor counteracts torque effect and provides positive Bank angle fuselage heading control Figure 3-3. Load factor. 4 Airflow from tail rotor Figure 3-2. Rotation direction. Thrust Thrust, like lift, is generated by the rotation of the main rotor At some point in training, the instructor should have the system. Point out to the student that in a helicopter thrust can student bring the helicopter to a high hover and explain that be forward, rearward, sideward, or vertical. The direction work load is greater and an increased left pedal requirement of the thrust is controlled with the cyclic. If cyclic control exists to hold a constant heading. The opposite can be shown to produce thrust is too great, lift is lost and the aircraft at a lower hover with a decrease in left pedal requirement to descends. Conversely, if too little cyclic control is made, hold the same heading. the aircraft begins a climb. Using visual aids, demonstrate how the resultant lift and thrust determines the direction of Weight movement of the helicopter. [Figure 3-4] As weight increases, the power required to produce lift needed to compensate for the added weight must also increase. This Explain to the student that the tail rotor also produces thrust. is accomplished through the use of the collective. Most The amount of thrust is variable through the application of 3-4

Total force 2. Profile drag—caused by the frictional resistance of the rotor blades passing through the air. Thrust Lift Weight 3. Induced drag—results from producing lift. Drag a. Blade tip vortices—pressure differential at tips of blades trying to equalize and produce a stream of vortices (turbulence). b. Induced flow—causes lift and total aerodynamic force to tilt further rearward on the airfoil. c. Total aerodynamic force tilted further backward at higher angles of attack. 4. Total drag—sum of induced, profile, and parasite. Resultant of drag and weight Use a graph that depicts drag/power relationship, and have the student identify the power requirements to overcome drag at various airspeeds. [Figure 3-1] Figure 3-4. Thrust. The following describes the relationship of each of the different types of drag to the airspeed of the aircraft. the antitorque pedals and is used to control the helicopter’s heading during hovering flight and trim during cruise flight. 1. Parasite drag—lowest point at a hover, but increases with airspeed. The major source of drag at higher Drag airspeeds. No discussion of aerodynamics is complete without its defining the three types of drag, how drag is created, and its 2. Profile drag—remains relatively constant at low effect on the aircraft. A certificated flight instructor (CFI) airspeed, but increases slightly at higher airspeed must become intimately familiar with the drag chart and how ranges. it relates to airspeed and power demands. Demonstrate this during the performance planning phase as the student has 3. Induced drag—major source of drag at a hover, but actual torque values to compare. Then, when the student is decreases with forward airspeed. flying the helicopter, apply the values that were computed and show the effect on the helicopter. A technique is to 4. Total drag—the sum total of induced, profile, and show how each flight control is affected by simple hover parasite drag. flight maneuvers. Demonstrate the change in torque that occurs between left and right pedal turns and explain why. a. Total drag decreases with forward airspeed Discuss how the cyclic is utilized to hold position over the until best rate of climb speed is reached. ground, while the pedals rotate the fuselage and control [Figure 3-1, Point E] heading. When excess power is available, demonstrate how the collective pitch can be applied to vary the hover height, b. Speeds greater than best rate of climb causes a or to accelerate the helicopter. It would be prudent to discuss decrease in overall efficiency due to increasing here that if no excess power is available, application of the parasite drag. collective then may be used to control the rotor rpm. This is done by changing the pitch in the blades. Over application Once the student understands the forces acting on the of the collective in a low power margin setting results in helicopter, provide examples of balanced and unbalanced flight rotor rpm decay and a loss of lift. Rotor rpm is the key to forces. For example, when hovering stationary in calm wind sustaining the aircraft in a steady state profile and should at a constant altitude, thrust is equal to drag and lift is equal to never be allowed to decay below minimum operating levels. weight. The aircraft is not moving vertically or horizontally. It is the key to life for a helicopter pilot! The aerodynamic forces are balanced. [Figure 3-5] The types of drag are: The student will also notice during hovering flight in a calm wind condition that with smaller American made helicopters 1. Parasite drag—drag created by the fuselage or any like the Robinson R-22, Bell 206, and Schweizer 300, the left nonlifting components (e.g., strut, skin friction, side of the aircraft will probably hang lower than the right. interference). This is due to the direction of the tail rotor thrust and the engineered mast tilt to compensate for translating tendency. 3-5

Total (resultant) force is changing, the pilot must apply cyclic to maintain position Weight over the ground and not allow the helicopter to drift in any one direction. The helicopter bank attitude might not be level due to crosswinds and translating tendency. The pitch attitude might not be level due to tailwinds or CG. The pilot must ensure that the tail rotor is clear of all obstacles and is not allowed to hang so low that it impacts the ground or other objects. For example, in steady state flight, the aircraft is maintaining a constant airspeed and constant altitude. The aerodynamic forces are balanced. Although the helicopter is moving, it is not accelerating or climbing. [Figure 3-6] Total (resultant) force Lift Figure 3-5. Balanced forces in hover. Thrust On much larger helicopters such as the BH-205, S-76, and Drag BK-117, in which an additional gearbox is used to raise the tail rotor up to the main rotor plane, the tilting of the fuselage Relative wind is not as prevalent. Weight Resultant of weight and drag The pitch attitude will vary depending on the loading of the helicopter. Many helicopters when flown single pilot will be Figure 3-6. Steady state—balanced forces. nose high at a hover. Conversely, they may be nose load when fully loaded. The center of gravity (CG) of the helicopter Any time opposing forces become unequal (unbalanced), determines which portion of the landing gear will come off acceleration results in direction of the greater force. If lift is the ground first. The CFI must pay particular attention to the greater than weight the helicopter climbs. If thrust is greater attitude of the helicopter as the student lifts it off the ground. than drag, the helicopter moves horizontally. Point out that If excess power is applied in other than a level attitude, the thrust can occur in any or all directions. For example, if the helicopter may proceed to roll beyond its dynamic rollover helicopter is moving sideways or backwards, thrust is in the limits. When lifted off the surface correctly and safely, the direction that it is moving. [Figure 3-7] pilot has the opportunity to lower the collective if a portion of the landing gear is attached or hung on the surface, thus Airfoil preventing a rollover incident from occurring. It is imperative that the CFI closely monitor the attitude of the helicopter Define and discuss the different types of airfoils with the and not the actions of the student. This simple action may student and stress the importance of using standardized determine whether or not the helicopter is allowed to stray terminology. An airfoil is a curved surface body or structure beyond the comfort level of the instructor to recover from a designed to produce a lift or thrust force when subjected to an particular action by the student. Never allow a student to go airflow. An instructor can check the student’s understanding beyond your comfort level. of airfoils and the terminology used to describe them by having the student draw and label the parts of an airfoil. Several inputs are required simultaneously as the aircraft is [Figure 3-8] Refer to the Pilot’s Handbook of Aeronautical brought to a hover. Stress to the student that these actions Knowledge and the Helicopter Flying Handbook (FAA- must occur without delay or coordinated flight will not 8083-21) for definitions and illustrations of airfoil design. occur. For example, as the collective is increased to lift the helicopter off the surface, the throttle must also be increased. Blade Twist Even if a governor accomplishes that action, the pilot still must Explain to the student that the rotor blade of a helicopter monitor the power instruments to ensure that no limits are is designed with a twist to relieve the stresses on the blade exceeded. With the increase in power, there is also an increase in torque and the tendency for the nose to turn to the right. The pilot must apply sufficient left pedal to maintain the helicopter heading. While this is occurring and the lift in the rotor system 3-6

Total (resultant) force Total (resultant) force Lift Weight Lift Thrust Relative wind Thrust Relative wind Drag Weight Resultant of weight and drag Figure 3-7. Acceleration or deceleration—unbalanced forces. Mean camber line Trailing edge These terms related to the rotor hub and blades are best Camber of upper surface discussed in the classroom and identified on the aircraft during a preflight. Camber of lower surface Airflow and Reactions in the Rotor Leading edge Chord line System Figure 3-8. Elements of an airfoil. When introducing and describing the airflow in a rotor system, the instructor must first identify the types of relative and distribute lifting force more evenly along the blade due wind. By defining and explaining the various air movements to the lift differential along the blade. Blade twist provides in a rotor system [Figure 3-9] and the relationship of air greater pitch angles at the blade root where velocity is low movement to an airfoil, the instructor establishes a foundation and smaller angles at the tip where blade velocity is higher. for more detailed discussions of aerodynamic principles. This increases the induced air velocity and blade loading near the inboard section of the blade. Induced flow Resultant relative wind Rotational relative wind Center of pressure Rotor Blade and Hub Definitions Chord line The CFI must be familiar with the following basic terms and Figure 3-9. Air movements in a rotor blade system. be able to explain them to the student. • The movement of a rotor blade through the air creates 1. Hub—the attachment point of the rotor blades. relative wind. Relative wind moves in a parallel but opposite direction to the movement of the rotor blade. 2. Tip of the blade—the farthest outboard section of the rotor blade. • The flow of air parallel to and opposite the flightpath of an airfoil is rotational relative wind. It always meets 3. Root of the blade—the section of the blade closest to the airfoil at a 90° angle. the hub and where the attachment point is located. • The component of the total relative wind velocity 4. Twist—the change in blade angle with respect to the created by forward flight velocity/airspeed is airspeed angle at the hub outward to the tip. relative wind. 5. Taper—the change (decrease) in blade chord with radial distance. 3-7

• Induced flow (downwash) is a downward component is changed on all blades (except tail rotor) simultaneously of air that is added to the rotational relative wind. by using the collective pitch control. Define this action as • Resultant relative wind is the airflow from rotation collective feathering and explain how it affects the overall (rotational relative wind) that is modified by induced lift of the rotor system. flow. Demonstrate how the cyclic pitch control causes a differential • Up flow (inflow) is airflow approaching the rotor disk change in the angle of individual blades (except tail rotor) from below as the result of some rate of descent. Up and define it as cyclic feathering. Stress to the student that flow also occurs as result of blades flapping down or cyclic feathering changes the attitude of the rotor system but an updraft. does not change the amount of lift. [Figure 3-11] A demonstration of the airflow in the following instances Point out how the angle of incidence for the tail rotor is helps the student understand the concept of relative wind: changed on all tail rotor blades simultaneously by using the antitorque pedals. • Airfoil moving in one direction • Stress that angle of incidence is a mechanical angle. • Rotating rotor blades [Figure 3-12] • Advancing blade • Remind the student that the AOA is the acute angle between the chord line of an airfoil and the resultant • Retreating blade relative wind. It can change with no change in the angle of incidence due to blade flapping and up/down • Relative winds are the same for tail rotor drafts. Rotor Blade Angles • Stress that angle of attack is an aerodynamic angle. [Figure 3-12] Angle of incidence is the acute angle between the chord line of the airfoil and the plane of rotation (tip path plane) or the Discuss lift at different AOAs. With the use of diagrams, an angle between the chord line of a blade and the relative wind. instructor can explain how the AOA affects the amount of Sometimes, this is referred to as the blade pitch angle. The lift. An easy demonstration of how the AOA affects lift is to angle is changed through rotation of the rotor blade around its remind the student of what happens if an arm is extended out spanwise axis, which is known as feathering. [Figure 3-10] of the window of a moving vehicle. Using guided discussion An instructor can use training aids to discuss the angle of and demonstration, ask the student what happens when the incidence in the classroom, but it is best demonstrated at palm of the hand is parallel to the ground and when it is the aircraft. Show the student how the angle of incidence rotated forward. Show the student how the hand rises until reaching the point at which it stalls and is just pulled rearward. Emphasize the following principles: 1. Larger angles of attack create more lift on an airfoil. 2. Smaller angles of attack result in a reduction of lift on the airfoil. 3. Exceeding the maximum (critical) angle can produce a stall. Maximum angle of attack is 15° to 20° on most airfoils. Blade rotates about its spanwise axis. Hovering Flight Blade pitch angle changes. It is essential for the student to understand the aerodynamics Figure 3-10. Rotor blade feathering. of hovering. Explain that for a helicopter to hover, lift produced by the rotor system must equal the total weight of the helicopter. An increase of blade pitch through application of collective increases the angle of incidence and generates the additional lift necessary to hover. As forces of lift and weight are in balance during stationary hover, those forces must be altered through application of collective either to climb or to descend. 3-8

Without Cyclic Feathering C Equal pitch in all blades Tip-path plane parallel to horizon C Horizon D B DB A A With Cyclic Feathering C A Point of smallest angle of blade pitch B Point of greatest angle blade displacement downward C Point of greatest angle of blade pitch D Point of greatest blade displacement upward DB Tip-path plane no longer parallel to horizon D C Horizon B A A Figure 3-11. Rotor blades with and without cyclic feathering. Angle of attack Resultant relative wind Center of pressure Angle of incidence Center of pressure Rotational relative wind Tip path plane Chord line Chord line Figure 3-12. Angle of attack and angle of incidence. 3-9

Describe to the student how, at a hover, the rotor-tip Describe the methods used to correct for translating tendency: vortex reduces effectiveness of the outer blade portions. [Figure 3-13] Vortices of the preceding blade affect the lift 1. Flight control rigging may be designed by the of the other blades in the rotor system. When maintaining manufacturer so the rotor disk is tilted slighted when a stationary hover, this continuous creation of vortices the cyclic control is centered to compensate for drift. combined with the ingestion of existing vortices is the primary cause of high power requirements for hovering. Rotor-tip 2. Transmission may be mounted so the mast is tilted vortices are part of the induced flow and increase induced drag. slightly when the helicopter fuselage is laterally level. Ensure that the student understands that, during hover, rotor blades move large amounts of air through the rotor system in 3. Pilot applies cyclic in the opposite direction to arrest a downward direction. This movement of air also introduces the drift. induced flow into relative wind, which alters the AOA of the airfoil. If there is no induced flow, relative wind is opposite Pendular Action and parallel to the flightpath of the airfoil. With a downward airflow altering the relative wind, the AOA is decreased Pendular action is the result of the CG being below the so that less aerodynamic force is produced. This change supporting structure (rotor system). Tilting the rotor in one requires an increase in collective pitch to produce enough direction results in the fuselage swinging in the opposite aerodynamic force to hover. direction. Stress to the student that this swinging is normal for helicopter operation since the helicopter fuselage is below No wind hover the rotor system and overcontrolling can result in exaggerated pendular action and should be avoided. The cyclic should Rotor-tip always be moved at a rate that allows the main rotor and vortex fuselage to move as a unit. Emphasize that the student should use slow, smooth, cyclic inputs while hovering. The student must understand that it is the relationship of the tip path plane to the horizon, and not the position of the fuselage, that determines the helicopter’s direction of travel. Downwash pattern equidistant 360° Coning Figure 3-13. Air movements in a rotor blade system. Coning is the upward flexing of the rotor blades. Point out to the student that coning is a normal phenomenon in all Translating Tendency or Drift rotors producing lift. The amount a blade cones is a resultant between lift and centrifugal force. When lift is stronger than Explain to the student that the thrusting characteristics of centrifugal force, the blade cones upward. When centrifugal a tail rotor during hovering flight create a tendency for force is stronger than lift, the blade moves downward, the helicopter to drift laterally, which is called translating reducing the coning angle. [Figure 3-14] tendency. A single-rotor helicopter with a counterclockwise rotating main rotor tends to drift laterally to the right. Stress Rotor shaft the cause: thrust exerted by the tail rotor compensates for main rotor torque. Translating tendency is to the left in a Centrifugal helicopter with a clockwise rotation of the main rotor. force Explain to the student that the helicopter fuselage will remain Lifting force on blade relatively level to slightly left side low. The amount of fuselage tilt varies between types and design of helicopters. Centrifugal The tip path plane of the main rotor will not be level and will force have to be adjusted accordingly with cyclic to counteract translating tendency and adverse wind conditions. The Blade (resultant) angle ability to tilt or adjust the wings of the helicopter allows the Coning helicopter to maintain its position over the ground. Centrifugal Lifting force on blade force Figure 3-14. Effect of centrifugal force and lift. 3-10

Explain the relationship between lift and excessive coning Coriolis Effect (Law of Conservation of and describe the causes of excessive coning to the student: Angular Momentum) • Low revolutions per minute (rpm)—less centrifugal The law of conservation of angular momentum states that force the value of angular momentum of a rotating body will not change unless external torques are applied. Explain to the • High gross weight—more lift needed student that, in other words, a rotating body continues to rotate with the same rotational velocity until some external • High G maneuvers—more lift needed force is applied to change the speed of rotation. Angular momentum can be expressed by the formula: • Turbulent air—point out to the student that any maneuvers requiring additional lift could lead to Mass Angular × Velocity × Radius Squared excessive coning. Discuss how changes in angular velocity, known as angular Give examples of excessive coning. Ensure the student acceleration or deceleration, take place if the mass of a understands: rotating body is moved closer to or further from the axis of rotation. The speed of the rotating mass increases or decreases • Flight conditions that require large amounts of lift may in proportion to the square of the radius. These forces cause lead to an excessive coning condition in the rotor. acceleration and deceleration. • As lift forces increase in the rotor, they overcome Tell the student that the coriolis effect may be stated in the the rigidity produced by centrifugal force. The rotor following terms. blades begin flexing upward, which could lead to an excessive coning angle. A mass moving radically— Guide the student in identifying the adverse effects of • Outward on a rotating disk exerts a force on its excessive coning in the rotor system. [Figure 3-15] surroundings in the direction opposite to rotation. Increased coning • Inward on a rotating disk exerts a force on its Smaller effective surroundings in the direction of rotation. rotor disk radius Lesser coning The major rotating elements in the system are the rotor blades. As the rotor begins to cone due to G-loading maneuvers, the Notice that the effective diameter of the rotor disk with increased diameter of the disk shrinks. Due to conservation of angular coning is less than the diameter of the other disk with less coning. momentum, the blades continue to travel the same speed even A smaller disk diameter has less potential to produce lift. though the blade tips have a shorter distance to travel due to Increased coning = decrease of total lift because of a reduced disk diameter. This action results in an increase in rotor rpm. Most pilots arrest this increase with an increase decrease in effective disk area in collective pitch. Lesser coning = more effective vertical lift Figure 3-15. Effects of coning. Conversely, as G-loading subsides and the rotor disk flattens out from the loss of G-load induced coning, the blade tips now 1. Loss of disk area. have a longer distance to travel at the same tip speed. This action results in a reduction of rotor rpm, and is corrected 2. Loss of total lift available. by reducing collective pitch. 3. Stress on blades. Ground Effect 4. Excessive stress forces in the rotor could lead to blade Define ground effect for the student as the increased cracking or blade separation from the rotor system. efficiency of the rotor system caused by interference of the airflow when near the ground. Discuss how ground effect 5. Excessive coning combined with low rotor rpm may permits relative wind to be more horizontal, the lift vector cause the blades to droop much lower than normal. to be more vertical, and induced drag to be reduced, all This condition is likely to occur at the end of an allowing the rotor system to be more efficient. Maximum autorotation and may allow the rotor blades to damage ground effect is achieved when hovering over smooth hard or remove the tail boom. surfaces. When hovering over such terrain as tall grass, trees, 6. Excessive coning may become unrecoverable in flight. 3-11

bushes, rough terrain, and water, ground effect is reduced. Figure 3-18 shows reactions to forces applied to a spinning Explain the two reasons for this phenomenon: induced flow rotor disk by control input or wind gusts. and vortex generation. [Figure 3-16] Reduced Altitude of Force Applied to Rotor Disk Aircraft Reaction rotor-tip one rotor vortex disk Up at nose Roll right diameter Up at tail Roll left or less Up on right side Nose up Up on left side Nose down Figure 3-18. Reactions to forces on a rotor disk. Figure 3-16. Airflow at altitude of one rotor disk diameter or less. Vertical Flight A student must understand that for climbing flight to occur, lift must be greater than weight. This is true whether at a hover or in steady state flight. Refer back to the forces acting on an aircraft in flight when explaining this concept. Gyroscopic Precession Forward Flight Explain to the student that precession occurs in rotating When explaining forward flight to the student, refer to the bodies that manifest an applied force 90° after application in section on forces acting on an aircraft in flight. Remind the the direction of rotation. Point out that although precession student that flight is the result of all forces, and that lift and is not a dominant force in helicopter aerodynamics, pilots thrust must be equal to the result of weight and drag for steady and designers must consider it since turning rotor systems state flight. Point out that acceleration in forward flight is the exhibit some of the characteristics of a spinning gyro. result of thrust being greater than drag. Figure 3-17 illustrates effects of precession on a typical rotor disk when force is applied at a given point. A downward Translational Lift force applied to the disk at point A results in a downward movement of the disk at point B. Aircraft designers take Translational lift is the additional lift obtained from increased gyroscopic precession into consideration and rig the cyclic efficiency of the rotor system with airspeed obtained either pitch control system to create an input 90° ahead of the by horizontal flight or by hovering into a wind. Describe desired action. the airflow patterns during directional flight and explain the causes of transitional lift. Downward movement R The relative wind entering the rotor system becomes more response here horizontal and results in the following: B esults in 1. A more vertical lift component Upward esults in Downward force force 2. Less induced drag ForwardC A applied applied 3. An increased AOA here here 4. Less turbulent air entering the rotor system R D Upward movement The airspeed range at which effective translational lift occurs is approximately 16–24 knots. As rotor efficiency increases Figure 3-17. Gyroscopic precession. and additional lift is produced due to more beneficial AOA, the rotor disk flaps upward causing the nose to pitch up; additional forward cyclic pressure is necessary at this point. As the airspeed increases and more lift is produced in the aft portion of the rotor disk, the nose tends to lower, requiring some aft cyclic to maintain an accelerative attitude and safe climb angle. 3-12

Provide the student with a graph depicting drag at different • Rotor blade action changes still air to a column of airspeeds. Using a graph like Figure 3-1 and guided descending air. discussion, ensure the student understands: This downward flow of air is called induced flow (downwash). 1. Each knot of forward airspeed increases the Emphasize that it is most pronounced at a hover under no- efficiency of the helicopter rotor system up to a wind conditions. point where retreating blade stall aerodynamics negate any further rotor system gains. Transverse Flow Effect 2. At effective translational lift (ETL), the rotor Advise the student that in forward flight, air passing through system completely outruns the recirculation of the rear portion of the rotor disk has a greater downwash angle old vortices and begins to operate in smooth, than air passing through the forward portion. Explain that undisturbed air. this difference in downwash angle is due to the fact that the greater the distance air flows over the rotor disk, the longer 3. Induced drag and total drag are reduced and the disk has to work on it and the greater the deflection is overall rotor efficiency increases. on the aft portion. 4. Increased efficiency continues with increased Ensure the student understands: airspeed until best climb speed is reached. [Figure 3-1, Point E] • Downward flow at the rear of the rotor disk causes a reduced AOA, resulting in less lift. 5. Airspeeds greater than best rate of climb speed result in lower efficiency of the helicopter due to • The front portion of the disk produces an increased AOA increased parasite drag. and more lift because airflow is more horizontal. Translational Thrust • These differences in lift between the fore and aft portions of the rotor disk are called transverse flow Translational thrust occurs as the helicopter transitions to effect. forward flight and the tail rotor begins to operate in smooth undisturbed air. As the takeoff proceeds, the pilot notices the • Transverse flow effect causes unequal drag in the nose yaw (to the left in a counterclockwise turning system). fore and aft portions of the rotor disk and results in This is the result of the increased translational thrust. To vibration easily recognizable by the pilot. regain trimmed flight, a little right pedal is normally required. At about this same aerodynamic point, the airflow begins • Transverse flow occurs between 10 and 20 knots. to smooth over the vertical stabilizer which carries some of the antitorque load in forward flight. This allows for slightly Stress to the student that transverse flow effect is most more reduction in tail rotor thrust, requiring further reduction noticeable during takeoff and, to a lesser degree, during in left pedal application. If there is no governor, a throttle deceleration for landing. Demonstrate how gyroscopic change may be required to reduce the rpm slightly since the precession causes the effects to be manifested 90° in the power demand was reduced. Depending on the helicopters direction of rotation, resulting in a right rolling motion position and airspeed, the rotor resultant rpm increase can requiring left cyclic input to maintain a more level fuselage be controlled by a slight increase in collective to maintain attitude and proper ground track. the rpm setting. Dissymmetry of Lift Induced Flow Dissymmetry of lift is the difference in lift that exists between Explain to the student that, at flat pitch, air leaves the trailing the advancing half of the rotor disk and the retreating half. edge of the rotor blade in the same direction it moved across Explain to the student how to determine the total relative wind the leading edge; thus, no lift or induced flow is being velocity on the advancing and retreating blades. produced. Demonstrate how, as blade pitch angle is increased, the rotor system induces a downward flow of air through the Discuss the relative wind velocity of blades at a hover and rotor blades, creating a downward component of air that is during translational flight. added to the rotational relative wind. Point out that because the blades are moving horizontally: Hover At a hover, relative wind velocity is: • Some of the air is displaced downward. • Approximately 400 knots at the tips. • The blades travel along the same path and pass a given point in rapid succession. • Approximately 300 knots one-fourth of the way in from the tips. 3-13

• Approximately 200 knots one-half of the way in from 1. Advancing blade—greater lift. the tips. 2. Retreating blade—less lift. • Approximately 100 knots three-fourths of the way in from the tips. Discuss roll and explain that American-designed helicopters (counterclockwise rotation) would roll to the left and pitch up • 0 knots at the center of the hub. if transverse flow and dissymmetry of lift were not overcome. Explain main rotor method of overcoming dissymmetry of Translational Flight lift (flapping). In translational flight, relative wind velocity: 1. Advancing blade produces more lift; when flapping • Is a combination of blade speed and airspeed. up, AOA decreases due to an increase in induced flow—loses lift. • Of the advancing blade is blade speed plus airspeed. 2. Retreating blades produce less lift; when flapping • Of the retreating blade is blade speed minus airspeed. down, AOA increases due to a decrease in induced flow—gains lift. Develop the relative wind velocity for the advancing and retreating blades in the 090° to 270° position. [Figure 3-19] 3. When blade flapping has compensated for dissymmetry Show area of reverse flow. Emphasize that equal lift is created of lift, the rotor disk is tilted to the rear. by advancing and retreating blades. 4. Cyclic feathering also compensates for dissymmetry Relative wind as a of lift (changes AOA) in the following ways: result of aircraft movement at a. Cyclic feathering changes the angle of incidence 120 knots differently around the rotor system. Airspeed 80 knots b. Forward cyclic decreases angle of incidence on Relative wind as a advancing blade, resulting in reduced AOA, and result of aircraft increases angle of incidence on retreating blade movement at resulting in increased AOA. 120 knots RDoitraetciotnioanl voeflrooctati 5. Tail rotor compensates for dissymmetry of lift 0 knots 180 kno on ity= 480 knots by both flapping and feathering at the same time, accomplished by rotor design and mounting. A delta hinge allows for flapping, which automatically introduces feathering of the tail rotor. 220 knots ts 280 knots 120 knots 2 O knots 380 knots Exercise caution during a low-altitude, high-speed takeoff as pitch attitude is very low. If an engine failure or partial 320 knots 400 knots power condition were experienced, the pilot would not be able to safely place the aircraft in an autorotative profile. A 400 knots = Rotational velocity 400 knots = Rotational velocity quick review of the height velocity diagram would be very − 80 knots = Aircraft airspeed + 80 knots = Aircraft airspeed useful here. 320 knots = Wind velocity 480 knots = Wind velocity Sideward, Rearward, and Turning Flight Explain to the student that to accomplish these different modes of flight, the rotor disk is tilted in the desired direction. The forces acting on the helicopter remain the same, only the resultant vectors are different. Sideward hovering flight requires more pedal control to maintain heading. Depending on the lateral speed of travel, some fuselage tilting can be expected. Rearward flight must be accomplished slowly and cautiously due to wind effects on the horizontal stabilizer and the lowering of the tail rotor making surface contact easier to occur. Figure 3-19. Relative wind velocity in forward flight. 3-14

Autorotation Explain to the student how the loss of engine power during the autorotation requires the pilot to use the pedal controls To help students better understand autorotation, divide it into to keep the helicopter in trim throughout the descent until four distinct phases: entry, steady-state descent, deceleration, the deceleration and touchdown point is reached, otherwise and touchdown. Guide the student through each phase, the increased drag would greatly increase the rate of descent. stressing how it is aerodynamically different from the others. Also explain how the fuselage tends to weathervane into the wind due to the vertical fin. Entry Guide the student through the entry or first stage of Deceleration autorotation and explain that this phase is entered after loss Explain to the student that to make an autorotative landing, of engine power. The loss of engine power and rotor rpm the pilot reduces airspeed and rate of descent just before are more pronounced when the helicopter is at high gross touchdown. Both actions can be partially accomplished by weight, high forward speed, or in high density altitude applying aft cyclic, which changes the attitude of the rotor conditions. Any of these conditions demand increased power disk in relation to the relative wind. During this maneuver, (high collective position) and a more abrupt reaction to loss the goal of the pilot shifts from maintaining an airspeed to of that power. In most helicopters, it takes only seconds for attaining a minimum ground speed for touchdown while rpm decay to bring rpm to a minimum safe range, requiring decreasing the rate of descent. Ensure the student understands a quick collective response from the pilot. The entry into that this attitude change: autorotation must be immediate and smooth by lowering the collective, adjusting the pedals for the loss of torque, • Inclines the lift vector of the rotor system to the rear, and adjusting the airspeed for the proper glide angle. The slowing forward speed. instructor should never initiate an autorotation, or simulated forced landing, unless there is suitable landing within glide • Increased airflow results in increasing rpm, which distance in the event of a powerplant or drive line failure. must be controlled with the collective. Discuss with the student the airflow and force vectors for • The lifting force of the rotor system is increased and a blade in this configuration. Remind the student that lift rate of descent is reduced. and drag vectors are large and the total aerodynamic force (TAF) is inclined well to the rear of the axis of rotation. An • During this stage of the autorotation, the lack of torque engine failure in this mode causes rapid rotor rpm decay. is noticeable and the aircraft fuselage may rotate Inform the student that to prevent this, a pilot must lower counterclockwise with application of the collective the collective quickly. due to frictional drag in the transmission, drive train, associated pumps, and generators (depending on type Explain to the student that as the helicopter begins to descend, of helicopter). Pedal application will be required to the airflow begins to flow upward and under the rotor system. maintain a heading aligned with the touchdown area. Any crosswind also causes the nose to weathervane into the wind due to lift produced by the vertical fin. Steady-State Descent Touchdown Airflow is now upward through the rotor disk because of the During this final phase of the autorotation with the airspeed descent. Once equilibrium is established, rate of descent and at a minimum as required for the conditions of the landing rotor rpm are stabilized, and the helicopter is descending at area, the cyclic stick is moved forward to place the aircraft in a constant angle. Angle of descent is normally 17° to 20°, a landing attitude while applying collective pitch to cushion depending on airspeed, density altitude, wind, and type of the landing. The height at which this phase is entered depends helicopter. The instructor should guide the student through on the size of the helicopter and the length of the tailboom. any RFM procedures or charted values for minimum rates The landing attitude varies between helicopter designs from of descent versus maximum glide distance if provided for touching the aft portion of the landing gear first as in an that helicopter. airplane, to a level attitude with all surfaces touching down at once. Each manufacturer has a preferred landing attitude During this phase of the autorotation, the aircraft is that must be used to. Heading control must be maintained maneuvered to reach a safe landing area by adjusting airspeed with the pedals to preclude the aircraft from rolling over once and making turns as appropriate while maintaining rotor rpm ground contact is made. at the proper range for the type of helicopter. Checklist items are also completed as time permits and a Mayday call made. 3-15

The instructor must ensure several conditions are met to allow 8. The student cannot be initially allowed to lower the the helicopter to arrive at this point: collective after touchdown. Once the helicopter is completely down and no longer subject to bouncing 1. The rate of descent, rotor rpm, and airspeed are all and flexing, some helicopter RFMs allow a slight within established parameters, as well as landing area decrease in collective to aid stopping and to decrease alignment and positioning. If any of these conditions low rpm blade flexing. are not within limits, re-engage the engine and make a power recovery or go-around. For a detailed description and illustration of autorotation, refer to chapter 11 of the Helicopter Flying Handbook (FAA- 2. The landing gear is and stays aligned with the ground 8083-21, as revised). track of the helicopter. Instructor Tips 3. The decelerating flare did not result in an increase in altitude (ballooning) or was not begun at too high of • Start the presentation of new material at the student’s an altitude. level of understanding. [Figure 3-20] 4. The student cannot be allowed to increase the • Check out Internet sites such as the National collective too soon, and the student must be prompted Aeronautics and Space Administration (NASA) to use available collective to cushion the landing soon Beginner’s Guide to Aeronautics (www.lerc.nasa. enough. gov/WWW/K-12/airplane/index.html) for graphics and simulations for use in explaining aeronautics. 5. The collective must be used to cushion the touchdown, but the student should not be allowed to hold the Chapter Summary helicopter off the surface. This chapter reviewed essential points to be taught during 6. The student must not be allowed to retain an excessive aerodynamics instruction. It provided the instructor decelerating attitude at too low an altitude allowing with additional material that can be used in explaining a tailboom or tail rotor strike. The student must be aerodynamic principles, as well as examples to enhance the taught how to begin the flare and then decrease the learning process. nose high attitude to a landing attitude. 7. The student cannot be allowed to move the cyclic aft after touchdown. This generally allows the rotor blades to dip aft over the tailboom and when occurring at the same time as the actual touchdown, results in a tailboom strike. Aerodynamics of Flight Objective Identify characteristics of translating tendency and methods of compensation in a single-rotor helicopter. The student demonstrates the consistent ability to identify and compensate for characteristics of translating tendency in a single-rotor helicopter. Content Classroom discussion: • Define translating thrust. • Provide instruction on the thrusting characteristics of a tail rotor during hovering flight. • Identify the methods used to overcome translating tendency. Postflight Discussion Critique student performance. Preview the next lesson. Assign Helicopter Flying Handbook Chapter 3, Helicopter Flight Controls. Figure 3-20. Sample lesson plan. 3-16